EXHIBIT 23.1 CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTANTS Tri-Union Development Corporation (formerly Tribo Petroleum Corporation) Houston, Texas We hereby consent to the incorporation by reference in the Registration Statements on Form S-4 No. 333-66282 and 333-66282-01 of Tri-Union Development Corporation (formerly Tribo Petroleum Corporation) of our report dated March 14, 2003, relating to the consolidated financial statements, which appears in this Form 10-K. We also consent to the reference to us under the caption "Experts" in the Prospectus. BDO Seidman, LLP Houston Texas March 31, 2003