1 Exhibit 23.1 CONSENT OF INDEPENDENT CERTIFIED PUBLIC ACCOUNTS To Foothill Independent Bancorp: We consent to the incorporation by reference in Registration Statement No. 2-89744 on Form S-8 filed March 1, 1984, Registration Statement No. 33-57586 on Form S-8 filed January 29, 1993, and Registration Statement No. 33-83854 on Form S-3 filed September 12, 1994, of our report dated January 22, 1999 on the consolidated financial statements of Foothill Independent Bancorp as of December 31, 1998 and 1997 and for each of the three years in the period ended December 31, 1998 included at Page 37 of its Annual Report on Form 10-K for the year ended December 31, 1998. /s/ VAVRINEK, TRINE, DAY & COMPANY ---------------------------------- VAVRINEK, TRINE, DAY & COMPANY Certified Public Accountants March 23, 1999 Rancho Cucamonga, California