| 1) | With                respect to the office building located at 1815 Capital Avenue, Omaha,                Nebraska, upon closing of the transactions contemplated by the Asset                Purchase Agreement, Aquila shall assign to Black Hills, and Black                Hills                shall assume, the Office Lease dated June 15, 1987, as amended, between                Aquila and MZ Nebraska Partners, and any subleases relating to such                leased                office space, as a part of the Purchased Assets and Assumed Obligations                (as those terms are defined in the Asset Purchase                Agreement).  Aquila shall retain all of its equity interests in                its subsidiary, UtilCo Group Inc., a general partner in MZ Nebraska                Partners. |
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| 2) | With                respect to an approximately fourteen mile long, 12” pipeline known as the                “Linc Line” or “PNG pipeline,” which is an intrastate natural gas pipeline                connecting from an interstate natural gas pipeline to the Lincoln,                Nebraska gas distribution system, at the closing of the transactions                contemplated by the Asset Purchase Agreement, Aquila shall cause                its                subsidiary that owns such pipeline to wind-up and dissolve, and Aquila                shall assign to Black Hills all of its right, title and interest                in and to                the PNG pipeline and all related easements, rights-of-way, franchises                and                equipment as a part of the Purchased Assets and Assumed Obligations                (as                those terms are defined in the Asset Purchase                Agreement). |
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| 3) | With                respect to Natural/Peoples Limited Liability Company, a Wyoming limited                liability company owning a compressed natural gas fueling station                in                Castle Rock, Colorado in which Aquila has a 50% interest, at the                closing                of the transactions contemplated by the Partnership Interests Purchase                Agreement, Aquila shall cause such interest to be assigned as part                of the                Purchased Assets and Assumed Obligations (as those terms are defined                in                the Partnership Interests Purchase                Agreement). |
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| 4) | With                respect to approximately $2.8 million in insurance proceeds available                to                Aquila from AEGIS for the reimbursement of future costs of remediation                of                environmental impacts relating to certain manufactured gas plants                currently or formerly owned by Aquila (or its predecessors in interest),                including manufactured gas plant sites to be acquired by Black Hills                and                Great Plains, each of Black Hills and Great Plains hereby acknowledges                receipt of a SEC 96-1 Estimated Costs of MGP Liability as of 12/31/06                of                Aquila (“MGP Spreadsheet”).  Based on the probable costs                identified for each site listed in such MGP Spreadsheet, Aquila and                Great                Plains agree to maintain and make available $980,000 of such amount                for                reimbursement of remediation costs, if any, incurred by Black Hills                after                the date of closing of the Asset Purchase Agreement associated with                the                manufactured gas plants identified in the MGP Spreadsheet and located                in                Kansas or Iowa.  This amount would be reduced by any spending on                the sites in these two states that is submitted to and paid by AEGIS                prior                to closing.   Any contributions from other potentially                responsible parties received prior to the date of closing of the                Asset                Purchase Agreement for remediation costs for the manufactured gas                plants                identified in the MGP Spreadsheet shall be allocated to, and paid                to,                Black Hills, if located in Nebraska, Kansas or Iowa, and allocated                to, and                retained by, Aquila, if located in Missouri, upon the date of closing                of                the Asset Purchase Agreement.  Any contributions from other                potentially responsible parties received after the date of closing                of the                Asset Purchase Agreement for the sites in Nebraska, Kansas or Iowa,                shall                be allocated to, and paid to, Black Hills, and for the sites in Missouri,                shall be allocated to, and retained by,                Aquila. |
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| 5) | With                respect to certain software applications for which Aquila holds licenses                from third parties, and without waiving or releasing any claims that                any                of the parties may have under the Asset Purchase Agreement or Partnership                Interests Purchase Agreement, Black Hills, Aquila and Great Plains                agree                to work collaboratively to identify the software applications subject                to                licenses with third parties, and to use commercially reasonable efforts                (which shall not, however, require Great Plains, Black Hills or Aquila                to                make any payments to licensors) to obtain the consent or approval                of the                licensors of such software applications toenable transfer at closing                of                the Asset Purchase Agreement of licenses from Aquila to Black Hills                that                are not contemplated to be utilized by Great Plains after the closing                of                the Asset Purchase                Agreement.   |
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**BLACK      HILLS CORPORATION **

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**GREAT      PLAINS ENERGY INCORPORATED**

| By:    | /s/                  Terry Bassham                                                                     |
|--------|--------------------------------------------------------------------------------------------------------|
| Name:  | Terry                  Bassham                                                                         |
| Title: | Executive                  Vice President - Finance and Strategic Development and                  CFO |

**GREGORY**
**      ACQUISITION CORP**

| By:    | /s/                Mark G. English     |
|--------|----------------------------------------|
| Name:  | Mark                G. English         |
| Title: | Secretary                and Treasurer |

**AQUILA,      INC.**

| By:    | /s/                Richard C. Green                 |
|--------|-----------------------------------------------------|
| Name:  | Richard                C. Green                     |
| Title: | Chairman                and Chief Executive Officer |

**AQUILA      COLORADO, LLC**

| By:    | /s/                Mike Cole |
|--------|------------------------------|
| Name:  | Mike                Cole     |
| Title: | President                    |