The first installment of Colusa County Property Tax is now due and payable. If not paid by 5 p.m., Wednesday, December 10, 2014, a 10% penalty will be added to each installment. Payments received in the mail must be postmarked on or before Wednesday, December 10, 2014. Payments can be made at 547 Market Street, Suite 111, Colusa, CA 95932.