EXHIBIT 23.1 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement No. 33-35357 of Giant Industries, Inc. on Form S-8 of our report dated April 26, 2000, appearing in this Annual Report on Form 11-K of Giant Industries, Inc. for the year ended December 31, 1999. DELOITTE & TOUCHE LLP Phoenix, Arizona May 26, 2000