(a)(3)

                            HIGH PLAINS CORPORATION

                               November 16, 2001

To Our Stockholders:

   On behalf of the Board of Directors of High Plains Corporation (the
"Company"), I am pleased to inform you that the Company has entered into an
Agreement and Plan of Merger, dated as of November 1, 2001 (the "Merger
Agreement"), with Abengoa, S.A. ("Abengoa"), ASA Environment & Energy Holding
AG (the "Purchaser") and Abengoa Biofuels Corp., a wholly owned subsidiary of
Purchaser, pursuant to which Purchaser has today commenced a cash tender offer
(the "Offer") to purchase all of the outstanding shares of common stock of the
Company (the "Shares") at a price of $5.6358 per Share. Under the Merger
Agreement, the Offer will be followed by a merger (the "Merger") in which any
remaining Shares (other than Shares held by the Company and by stockholders
who perfect appraisal rights under Kansas law) will be converted into the
right to receive $5.6358 in cash. Consummation of the Offer is subject to
certain conditions, as more fully described in the enclosed materials,
including the condition that the number of Shares validly tendered and not
withdrawn prior to the expiration date of the Offer shall not be less than 81%
of the total Shares then issued and outstanding.

   The Board of Directors has unanimously determined that the Offer and the
Merger are advisable and fair to and in the best interests of the Company's
stockholders, and has approved the Offer and the Merger. The Board of
Directors recommends that the stockholders of the Company accept the Offer and
tender their Shares pursuant to the Offer.

   In arriving at its recommendation, the Board of Directors gave careful
consideration to the factors described in the enclosed Schedule 14D-9,
including, among other things, the written opinion of Goldsmith Agio Helms
Securities, Inc., the Company's financial advisor, that, subject to the
assumptions, factors and limitations set forth therein, the consideration to
be received by holders of Shares in the Offer and the Merger is fair to such
holders from a financial point of view. The opinion of Goldsmith Agio Helms
Securities, Inc. is attached to the Schedule 14D-9. The Schedule 14D-9
contains other important information relating to the Offer, and you are
encouraged to read the Schedule 14D-9 carefully.

   In addition to the enclosed Schedule 14D-9, also enclosed is the Offer to
Purchase and related materials of Abengoa and Purchaser, including a Letter of
Transmittal, to be used for tendering your Shares in the Offer. These
documents state the terms and conditions of the Offer and provide instructions
as to how to tender your Shares. We urge you to read these documents carefully
in making your decision with respect to tendering your Shares pursuant to the
Offer.

   If you need assistance with the tendering of your Shares, please contact
the information agent for the Offer at its address or telephone number
appearing on the back cover of the Offer to Purchase.

   On behalf of the Board of Directors and management of the Company, we thank
you for your support.

                                          Very truly yours,

                                          President and Chief Executive
                                           Officer