June 29, 2007 Steven Helmers, Esq. Mark English, Esq. Black Hills Corporation Great Plains Energy Incorporated

Exhibit 10.1.1

June 29, 2007

Xxxxxx Xxxxxxx, Esq.                                                        Xxxx Xxxxxxx, Esq.

Black Hills Corporation                                                     Great Plains Energy Incorporated

000 Xxxxx Xxxxxx                                                                 0000 Xxxxxx

Xxxxx Xxxx, XX 00000                                                         Xxxxxx Xxxx, XX 00000

Re: Partnership Interests Purchase Agreement and Asset Purchase Agreement (collectively, the "Agreements") by and among Aquila, Inc. ("Aquila"), Black Hills Corporation ("Black Hills"), Great Plains Energy Incorporated ("Great Plains") and Xxxxxxx Acquisition Corp. ("Xxxxxxx")

Dear Xxxxx and Xxxx:

Under the terms of the Agreements, Black Hills and Great Plains are to attach schedules setting forth Retained Agreements and Shared Agreements prior to July 1, 2007. We recognize that this deadline may be implausible and therefore propose extending the date set forth under section 2.2(1) and 8.5(d) of the Agreements to September 1, 2007. Of course we will work to assist you in the identification process.

If you are in agreement, please sign below on the attached signature page where indicated and return a copy of this letter to me by fax or e-mail.

Very truly yours,

AQUILA, INC.

By:  /s/ Xxxxxxxxxxx X. Xxxxx

Name:  Xxxxxxxxxxx X. Xxxxx

Title:                      General Counsel

Signature Page to June 26, 2007 Letter Agreement

ACKNOWLEDGED, CONSENTED TO, AND ACCEPTED BY:

BLACK HILLS CORPORATION

By:  /s/  Xxxxxx X. Xxxxx

Name:    Xxxxxx X. Xxxxx

Title:      Pres. and COO Retail

GREAT PLAINS ENERGY INCORPORATED

By:  /s/ Xxxxxxx X. Xxxxx

Name:   Xxxxxxx X. Xxxxx

Title:     Treasurer and Chief Risk Officer

XXXXXXX ACQUISITION CORP.

By:  /s/ Xxxx X. English

Name:   Xxxx X. English

Title:     Secretary and Treasurer