Exhibit 4.8 CERTIFICATE OF TRUST OF IDACORP TRUST III THIS CERTIFICATE OF TRUST of IDACORP Trust III (the "Trust"), dated as of September 24, 1998, is being duly executed and filed by the undersigned, as trustees, to form a business trust under the Delaware Business Trust Act (12 Del. C. ss. 3801, et seq.). (i) Name. The name of the business trust formed hereby is IDACORP Trust III. (ii) Delaware Trustee. The name and business address of the trustee of the Trust with a principal place of business in the State of Delaware are: Bankers Trust (Delaware) E.A. Delle Donne Corporate Center Montgomery Building 1101 Centre Road, Suite 200 Wilmington, DE 19805-1266 (iii) Counterparts. This Certificate of Trust may be executed in one or more counterparts, all of which together shall constitute one and the same instrument. (iv) Effective Date. This Certificate of Trust shall be effective as of its filing. IN WITNESS WHEREOF, the undersigned, being the trustees of the Trust, have executed this Certificate of Trust as of the date first above written. Bankers Trust Company, not in its individual capacity but solely as Trustee By: /s/ James C. McDonough ----------------------------------- Name: James C. McDonough Title: Vice President Bankers Trust (Delaware), not in its individual capacity but solely as Trustee By: /s/ M. Lisa Wilkins ----------------------------------- Name: M. Lisa Wilkins Title: Assistant Secretary /s/ J. LaMont Keen ----------------------------------- J. LaMont Keen, not in his individual capacity but solely as Trustee