Exhibit 10.1

PROMISSORY NOTE

$5,000,000.00

March 14, 2011

Roanoke Gas Company

519 Kimball Avenue

Roanoke, Virginia 24016

(Hereinafter referred to as “Borrower”)

Wells Fargo Bank, N.A.

Roanoke, Virginia 24019

(Hereinafter referred to as “Bank”)

Borrower promises to pay to the order of Bank, in lawful money of the United States of America by mailing to the address specified hereinafter or wherever else Bank may specify, the sum of Five Million and No/100 Dollars ($5,000,000.00) or such sum as may be advanced and outstanding from time to time, with interest on the unpaid principal balance at the rate and on the terms provided in this Promissory Note (including all renewals, extensions or modifications hereof, this “Note”).

RENEWAL/MODIFICATION. This Promissory Note renews, extends and/or modifies that certain Promissory Note by and between Roanoke Gas Company and Wells Fargo Bank, N.A., successor in interest by merger to Wachovia Bank, N.A. dated March 26, 2010, in the original amount of $13,000,000.00, as renewed and/or extended from time to time (the “Original Promissory Note”). This Promissory Note is not a novation.

LINE OF CREDIT ADVANCES. Borrower may borrow, repay and reborrow, and, upon the request of Borrower, Bank shall advance and readvance under this Note from time to time until the maturity hereof (each an “Advance” and together the “Advances”), so long as the total principal balance outstanding under this Note at any one time does not exceed (i) $5,000,000.00 from the date of this Note through and including March 31, 2011; (ii) $1,000,000.00 from April 1, 2011 through and including September 23, 2011; (iii) $3,000,000.00 from September 24, 2011 through and including October 24, 2011; (iv) $5,000,000.00 from October 25, 2011 through and and including January 24, 2012; and (v) $3,000,000.00 from January 25, 2012 through and including February 23, 2012; and (vi) thereafter beginning February 24, 2012 the principal amount available for lending under this Note will be reduced to $1,000,000.00 through and including the maturity date, March 31, 2012. Bank’s obligation to make Advances under this Note shall terminate if Borrower is in Default. As of the date of each proposed Advance, Borrower shall be deemed to represent that each representation made in the Loan Documents is true as of such date.

If Borrower subscribes to Bank’s cash management services and such services are applicable to this line of credit, the terms of such service shall control the manner in which funds are transferred between the applicable demand deposit account and the line of credit for credit or debit to the line of credit.

USE OF PROCEEDS. Borrower shall use the proceeds of the loan(s) evidenced by this Note for the commercial purposes of Borrower, as follows: to finance inventory and accounts receivable.

INTEREST RATE. Interest shall accrue on the unpaid principal balance of this Note from the date hereof at the 1-month LIBOR Market Index Rate plus 1.00%, as that rate may change from day to day in accordance with changes in the 1-month LIBOR Market Index Rate (“Interest Rate”). 1-month “LIBOR Market Index Rate”, for any day, means the rate for 1 month U.S. dollar deposits as reported on Telerate Successor Page 3750 as of 11:00 a.m., London time, on such day, or if such day is not a London business day, then the immediately preceding London business day (or if not so reported, then as determined by Bank from another recognized source or interbank quotation).

DEFAULT RATE. In addition to all other rights contained in this Note, if a Default (as defined herein) occurs and as long as a Default continues, all outstanding Obligations, other than Obligations under any swap agreements (as defined in 11 U.S.C. § 101, as in effect from time to time) between Borrower and Bank or its affiliates, shall bear interest at the Interest Rate plus 3% (“Default Rate”). The Default Rate shall also apply from acceleration until the Obligations or any judgment thereon is paid in full.

INTEREST AND FEE(S) COMPUTATION (ACTUAL/360). Interest and fees, if any, shall be computed on the basis of a 360-day year for the actual number of days in the applicable period (“Actual/360 Computation”). The Actual/360 Computation determines the annual effective interest yield by taking the stated (nominal) rate for a year’s period and then dividing said rate by 360 to determine the daily periodic rate to be applied for each day in the applicable period. Application of the Actual/360 Computation produces an annualized effective rate exceeding the nominal rate.

REPAYMENT TERMS. This Note shall be due and payable in consecutive monthly payments of accrued interest only, commencing on April 1, 2011, and continuing on the same day of each month thereafter until fully paid. Principal payments will be due and payable from time to time in amounts sufficient to satisfy the availability limitations described in the Line of Credit paragraph above. In any event, all principal and accrued interest shall be due and payable on March 31, 2012.

EXTENSION AND RENEWAL. Bank may, at Bank’s discretion, renew or extend this Note by written notice to Borrower. Such renewal or extension will be effective as of the maturity date of this Note. Borrower will be deemed to have accepted the terms of such extensions and renewals if Borrower does not deliver to Bank written rejection of such renewal or extension within 10 days following the date of the written notice of such changes, or if Borrower draws additional funds following receipt of such notice. After any renewal or extension of Borrower’s obligations under this Note, the term “maturity date” as used in this Note will mean the new maturity date set forth in the written notice of extension or renewal of this Note. The Note may be modified, extended and renewed repeatedly in this manner.

AVAILABILITY FEE. Borrower shall pay to Bank quarterly an availability fee equal to 0.15% per annum on the difference between (i) the face amount of this Note and (ii) the outstanding principal balance of this Note, for each day during the preceding calendar quarter or portion thereof, commencing on June 1, 2011 and continuing on the same day of each quarter thereafter, with a final payment due and payable on the date that all principal and accrued interest is paid in full.

APPLICATION OF PAYMENTS. Monies received by Bank from any source for application toward payment of the Obligations shall be applied to accrued interest and then to principal. If a Default occurs, monies may be applied to the Obligations in any manner or order deemed appropriate by Bank.

If any payment received by Bank under this Note or other Loan Documents is rescinded, avoided or for any reason returned by Bank because of any adverse claim or threatened action, the returned payment shall remain payable as an obligation of all persons liable under this Note or other Loan Documents as though such payment had not been made.

DEFINITIONS. Loan Documents. The term “Loan Documents”, as used in this Note and the other Loan Documents, refers to all documents executed in connection with or related to the loan evidenced by this Note and any prior notes which evidence all or any portion of the loan evidenced by this Note, and any letters of credit issued pursuant to any loan agreement to which this Note is subject, any applications for such letters of credit and any other documents executed in connection therewith or related thereto, and may include, without limitation, a commitment letter that survives closing, a loan agreement, this Note, guaranty agreements, security agreements, security instruments, financing statements, mortgage instruments, any renewals or modifications, whenever any of the foregoing are executed, but does not include swap agreements (as defined in 11 U.S.C. § 101, as in effect from time to time). Obligations. The term “Obligations”, as used in this Note and the other Loan Documents, refers to any and all

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indebtedness and other obligations under this Note, all other obligations under any other Loan Document(s), and all obligations under any swap agreements (as defined in 11 U.S.C. § 101, as in effect from time to time) between Borrower and Bank, or its affiliates, whenever executed. Certain Other Terms. All terms that are used but not otherwise defined in any of the Loan Documents shall have the definitions provided in the Uniform Commercial Code.

LATE CHARGE. If any payments are not timely made, Borrower shall also pay to Bank a late charge equal to 5% of each payment past due for 8 or more days. This late charge shall not apply to payments due at maturity or by acceleration hereof.

Acceptance by Bank of any late payment without an accompanying late charge shall not be deemed a waiver of Bank’s right to collect such late charge or to collect a late charge for any subsequent late payment received.

ATTORNEYS’ FEES AND OTHER COLLECTION COSTS. Borrower shall pay all of Bank’s reasonable expenses actually incurred to enforce or collect any of the Obligations including, without limitation, reasonable arbitration, paralegals’, attorneys’ and experts’ fees and expenses, whether incurred without the commencement of a suit, in any trial, arbitration, or administrative proceeding, or in any appellate or bankruptcy proceeding.

USURY. If at any time the effective interest rate under this Note would, but for this paragraph, exceed the maximum lawful rate, the effective interest rate under this Note shall be the maximum lawful rate, and any amount received by Bank in excess of such rate shall be applied to principal and then to fees and expenses, or, if no such amounts are owing, returned to Borrower.

DEFAULT. If any of the following occurs, a default (“Default”) under this Note shall exist: Nonpayment; Nonperformance. The failure of timely payment or performance of the Obligations or Default under this Note or any other Loan Documents. False Warranty. A warranty or representation made or deemed made in the Loan Documents or furnished Bank in connection with the loan evidenced by this Note proves materially false, or if of a continuing nature, becomes materially false. Cross Default. At Bank’s option, any default in payment or performance of any obligation under any other loans, contracts or agreements of Borrower, any Subsidiary or Affiliate of Borrower, any general partner of or the holder(s) of the majority ownership interests of Borrower with Bank or its affiliates (“Affiliate” shall have the meaning as defined in 11 U.S.C. § 101, as in effect from time to time, except that the term “Borrower” shall be substituted for the term “Debtor” therein; “Subsidiary” shall mean any business in which Borrower holds, directly or indirectly, a controlling interest). Cessation; Bankruptcy. The death of, appointment of a guardian for, dissolution of, termination of existence of, loss of good standing status by, appointment of a receiver for, assignment for the benefit of creditors of, or commencement of any bankruptcy or insolvency proceeding by or against Borrower, its Subsidiaries or Affiliates, if any, or any general partner of or the holder(s) of the majority ownership interests of Borrower, or any party to the Loan Documents. Material Capital Structure or Business Alteration. Without prior written consent of Bank, (i) a material alteration in the kind or type of Borrower’s business or that of Borrower’s Subsidiaries or Affiliates, if any; (ii) the sale of substantially all of the business or assets of Borrower, any of Borrower’s Subsidiaries or Affiliates or any guarantor, or a material portion (10% or more) of such business or assets if such a sale is outside the ordinary course of business of Borrower, or any of Borrower’s Subsidiaries or Affiliates or any guarantor, or more than 50% of the outstanding stock or voting power of or in any such entity in a single transaction or a series of transactions; (iii) the acquisition of substantially all of the business or assets or more than 50% of the outstanding stock or voting power of any other entity; or (iv) should any Borrower or any of Borrower’s Subsidiaries or Affiliates or any guarantor enter into any merger or consolidation. Material Adverse Change. Bank determines in good faith, in its sole discretion, that the prospects for payment or performance of the Obligations are impaired or there has occurred a material adverse change in the business or prospects of Borrower, financial or otherwise.

REMEDIES UPON DEFAULT. If a Default occurs under this Note or any Loan Documents, Bank may at any time thereafter, take the following actions: Bank Lien. Foreclose its security interest or lien against Borrower’s deposit accounts and investment property without notice. Acceleration Upon Default.

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Accelerate the maturity of this Note and, at Bank’s option, any or all other Obligations, other than Obligations under any swap agreements (as defined in 11 U.S.C. § 101, as in effect from time to time) between Borrower and Bank, or its affiliates, which shall be due in accordance with and governed by the provisions of said swap agreements; whereupon this Note and the accelerated Obligations shall be immediately due and payable; provided, however, if the Default is based upon a bankruptcy or insolvency proceeding commenced by or against Borrower or any guarantor or endorser of this Note, all Obligations (other than Obligations under any swap agreement as referenced above) shall automatically and immediately be due and payable. Cumulative. Exercise any rights and remedies as provided under the Note and other Loan Documents, or as provided by law or equity.

ANNUAL FINANCIAL STATEMENTS. Borrower shall deliver to Bank, within 90 days after the close of each fiscal year, unaudited management-prepared financial statements reflecting its operations during such fiscal year, including, without limitation, a balance sheet, profit and loss statement and statement of cash flows, with supporting schedules and in reasonable detail, prepared in conformity with generally accepted accounting principles, applied on a basis consistent with that of the preceding year. If unaudited statements are required, such statements shall be certified as to their correctness by a principal financial officer of Borrower.

PERIODIC FINANCIAL STATEMENTS. Borrower shall deliver to Bank, within 45 days after the end of each fiscal quarter, unaudited management-prepared quarterly financial statements including, without limitation, a balance sheet, profit and loss statement and statement of cash flows, with supporting schedules; all in reasonable detail and prepared in conformity with generally accepted accounting principles, applied on a basis consistent with that of the preceding year. Such statements shall be certified as to their correctness by a principal financial officer of Borrower and in each case, if audited statements are required, subject to audit and year-end adjustments.

FINANCIAL AND OTHER INFORMATION. Borrower shall deliver to Bank such information as Bank may reasonably request from time to time, including without limitation, financial statements and information pertaining to Borrower’s financial condition. Such information shall be true, complete, and accurate.

WAIVERS AND AMENDMENTS. No waivers, amendments or modifications of this Note and other Loan Documents shall be valid unless in writing and signed by an officer of Bank. No waiver by Bank of any Default shall operate as a waiver of any other Default or the same Default on a future occasion. Neither the failure nor any delay on the part of Bank in exercising any right, power, or remedy under this Note and other Loan Documents shall operate as a waiver thereof, nor shall a single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or remedy.

Except to the extent otherwise provided by the Loan Documents or prohibited by law, each Borrower and each other person liable under this Note waives presentment, protest, notice of dishonor, demand for payment, notice of intention to accelerate maturity, notice of acceleration of maturity, notice of sale and all other notices of any kind. Further, each agrees that Bank may (i) extend, modify or renew this Note or make a novation of the loan evidenced by this Note, and/or (ii) grant releases, compromises or indulgences with respect to any collateral securing this Note, or with respect to any Borrower or other person liable under this Note or any other Loan Documents, all without notice to or consent of each Borrower and other such person, and without affecting the liability of each Borrower and other such person; provided, Bank may not extend, modify or renew this Note or make a novation of the loan evidenced by this Note without the consent of the Borrower, or if there is more than one Borrower, without the consent of at least one Borrower; and further provided, if there is more than one Borrower, Bank may not enter into a modification of this Note which increases the burdens of a Borrower without the consent of that Borrower.

MISCELLANEOUS PROVISIONS. Assignment. This Note and the other Loan Documents shall inure to the benefit of and be binding upon the parties and their respective heirs, legal representatives, successors and assigns. Bank’s interests in and rights under this Note and the other Loan Documents are freely assignable, in whole or in part, by Bank. In addition, nothing in this Note or any of the other Loan Documents shall prohibit Bank from pledging or assigning this Note or any of the other Loan

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Documents or any interest therein to any Federal Reserve Bank. Borrower shall not assign its rights and interest hereunder without the prior written consent of Bank, and any attempt by Borrower to assign without Bank’s prior written consent is null and void. Any assignment shall not release Borrower from the Obligations. Organization; Powers. Borrower represents that Borrower (i) is (a) an adult individual and is sui juris, or (b) a corporation, general partnership, limited partnership, limited liability company or other legal entity, duly organized, validly existing and in good standing under the laws of its state of organization, and is authorized to do business in each other jurisdiction wherein its ownership of property or conduct of business legally requires such organization (ii) has the power and authority to own its properties and assets and to carry on its business as now being conducted and as now contemplated; and (iii) has the power and authority to execute, deliver and perform, and by all necessary action has authorized the execution, delivery and performance of, all of its obligations under this Note and any other Loan Document to which it is a party. Compliance with Laws. Borrower represents that Borrower and any subsidiary and affiliate of Borrower and any guarantor are in compliance in all respects with all federal, state and local laws, rules and regulations applicable to its properties, operations, business, and finances, including, without limitation, all applicable federal, state and local laws and regulations intended to protect the environment; and the Employee Retirement Income Security Act of 1974, as amended (“ERISA”), if applicable. None of Borrower, or any subsidiary or affiliate of Borrower or any guarantor is a Sanctioned Person or has any of its assets in a Sanctioned Country or does business in or with, or derives any of its operating income from investments in or transactions with, Sanctioned Persons or Sanctioned Countries in violation of economic sanctions administered by OFAC. The proceeds from the Loan will not be used to fund any operations in, finance any investments or activities in, or make any payments to, a Sanctioned Person or a Sanctioned Country. “OFAC” means the U.S. Department of the Treasury’s Office of Foreign Assets Control. “Sanctioned Country” means a country subject to a sanctions program identified on the list maintained by OFAC and available at http://www.treas.gov/offices/enforcement/ofac/programs/index.shtml, or as otherwise published from time to time. “Sanctioned Person” means (i) a person named on the list of Specially Designated Nationals or Blocked Persons maintained by OFAC available at http://www.treas.gov/offices/enforcement/ofac/sdn/index.shtml, or as otherwise published from time to time, or (ii) (A) an agency of the government of a Sanctioned Country, (B) an organization controlled by a Sanctioned Country, or (C) a person resident in a Sanctioned Country, to the extent subject to a sanctions program administered by OFAC. Applicable Law; Conflict Between Documents. This Note and, unless otherwise provided in any other Loan Document, the other Loan Documents shall be governed by and interpreted in accordance with federal law and, except as preempted by federal law, the laws of the state named in Bank’s address on the first page hereof without regard to that state’s conflict of laws principles. If the terms of this Note should conflict with the terms of any loan agreement or any commitment letter that survives closing, the terms of this Note shall control. Borrower’s Accounts. Except as prohibited by law, Borrower grants Bank a security interest in all of Borrower’s deposit accounts and investment property with Bank and any of its affiliates. Swap Agreements. All swap agreements (as defined in 11 U.S.C. § 101, as in effect from time to time), if any, between Borrower and Bank or its affiliates are independent agreements governed by the written provisions of said swap agreements, which will remain in full force and effect, unaffected by any repayment, prepayment, acceleration, reduction, increase or change in the terms of this Note, except as otherwise expressly provided in said written swap agreements, and any payoff statement from Bank relating to this Note shall not apply to said swap agreements except as otherwise expressly provided in such payoff statement. Jurisdiction. Borrower irrevocably agrees to non-exclusive personal jurisdiction in the state named in the Bank’s address on the first page hereof. Severability. If any provision of this Note or of the other Loan Documents shall be prohibited or invalid under applicable law, such provision shall be ineffective but only to the extent of such prohibition or invalidity, without invalidating the remainder of such provision or the remaining provisions of this Note or other such document. Payments. All payments shall be mailed to Bank at Commercial Loan Services, P. O. Box 740502, Atlanta, GA 30374-0502; or other such address as provided by Bank in writing. Notices. Any notices to Borrower shall be sufficiently given, if in writing and mailed or delivered to the Borrower’s address shown above or such other address as provided hereunder, and to Bank, if in writing and mailed or delivered to Wells Fargo Bank, N.A., Mail Code VA7628 / R4057-01Z, P. O. Box 13327, Roanoke, VA 24040 or Wells Fargo Bank, N.A., Mail Code VA7628 / R4057-01Z, 7711 Plantation Road, Roanoke, VA 24019 or such other address as Bank may specify in writing from time to time. Notices to Bank must include the mail code. In the event that Borrower changes Borrower’s address at

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any time prior to the date the Obligations are paid in full, Borrower agrees to promptly give written notice of said change of address by registered or certified mail, return receipt requested, all charges prepaid. Plural; Captions. All references in the Loan Documents to Borrower, guarantor, person, document or other nouns of reference mean both the singular and plural form, as the case may be, and the term “person” shall mean any individual, person or entity. The captions contained in the Loan Documents are inserted for convenience only and shall not affect the meaning or interpretation of the Loan Documents. Advances. Bank may, in its sole discretion, make other advances which shall be deemed to be advances under this Note, even though the stated principal amount of this Note may be exceeded as a result thereof. Posting of Payments. All payments received during normal banking hours after 2:00 p.m. local time at the address for payments set forth above shall be deemed received at the opening of the next banking day. Joint and Several Obligations. If there is more than one Borrower, each is jointly and severally obligated together with all other parties obligated for the Obligations. Fees and Taxes. Borrower shall promptly pay all documentary, intangible recordation and/or similar taxes on this transaction whether assessed at closing or arising from time to time. LIMITATION ON LIABILITY; WAIVER OF PUNITIVE DAMAGES. EACH OF THE PARTIES HERETO, INCLUDING BANK BY ACCEPTANCE HEREOF, AGREES THAT IN ANY JUDICIAL, MEDIATION OR ARBITRATION PROCEEDING OR ANY CLAIM OR CONTROVERSY BETWEEN OR AMONG THEM THAT MAY ARISE OUT OF OR BE IN ANY WAY CONNECTED WITH THIS AGREEMENT, THE LOAN DOCUMENTS OR ANY OTHER AGREEMENT OR DOCUMENT BETWEEN OR AMONG THEM OR THE OBLIGATIONS EVIDENCED HEREBY OR RELATED HERETO, IN NO EVENT SHALL ANY PARTY HAVE A REMEDY OF, OR BE LIABLE TO THE OTHER FOR, (1) INDIRECT, SPECIAL OR CONSEQUENTIAL DAMAGES OR (2) PUNITIVE OR EXEMPLARY DAMAGES. EACH OF THE PARTIES HEREBY EXPRESSLY WAIVES ANY RIGHT OR CLAIM TO PUNITIVE OR EXEMPLARY DAMAGES THEY MAY HAVE OR WHICH MAY ARISE IN THE FUTURE IN CONNECTION WITH ANY SUCH PROCEEDING, CLAIM OR CONTROVERSY, WHETHER THE SAME IS RESOLVED BY ARBITRATION, MEDIATION, JUDICIALLY OR OTHERWISE. Patriot Act Notice. To help fight the funding of terrorism and money laundering activities, Federal law requires all financial institutions to obtain, verify, and record information that identifies each person who opens an account. For purposes of this section, account shall be understood to include loan accounts. Telephone Communication Monitoring. Borrower agrees that Borrower’s telephone communications with Bank may be monitored and/or recorded to improve customer service and security. Final Agreement. This Note and the other Loan Documents represent the final agreement between the parties and may not be contradicted by evidence of prior, contemporaneous or subsequent agreements of the parties. There are no unwritten agreements between the parties.

WAIVER OF JURY TRIAL. TO THE EXTENT PERMITTED BY APPLICABLE LAW, EACH OF BORROWER BY EXECUTION HEREOF AND BANK BY ACCEPTANCE HEREOF, KNOWINGLY, VOLUNTARILY AND INTENTIONALLY WAIVES ANY RIGHT EACH MAY HAVE TO A TRIAL BY JURY IN RESPECT OF ANY LITIGATION BASED ON, OR ARISING OUT OF, UNDER OR IN CONNECTION WITH THIS NOTE, THE LOAN DOCUMENTS OR ANY AGREEMENT CONTEMPLATED TO BE EXECUTED IN CONNECTION WITH THIS NOTE, OR ANY COURSE OF CONDUCT, COURSE OF DEALING, STATEMENTS (WHETHER VERBAL OR WRITTEN) OR ACTIONS OF ANY PARTY WITH RESPECT HERETO. THIS PROVISION IS A MATERIAL INDUCEMENT TO BANK TO ACCEPT THIS NOTE. EACH OF THE PARTIES AGREES THAT THE TERMS HEREOF SHALL SUPERSEDE AND REPLACE ANY PRIOR AGREEMENT RELATED TO ARBITRATION OF DISPUTES BETWEEN THE PARTIES CONTAINED IN ANY LOAN DOCUMENT OR ANY OTHER DOCUMENT OR AGREEMENT HERETOFORE EXECUTED IN CONNECTION WITH, RELATED TO OR BEING REPLACED, SUPPLEMENTED, EXTENDED OR MODIFIED BY, THIS NOTE.

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IN WITNESS WHEREOF, Borrower, on the day and year first above written, has caused this Note to be duly executed under seal.

Work Request / Tracking #: 2277231

CAT - Deal # 1497853 Facility #: 1266368

Obligor #: 7181150009 Obligation #: 744128

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