Lassen Medical Clinic - Red Bluff Location. 2450 Sister Mary Columba Drive. Red Bluff, CA 96080. Phone: (530) 527-0414. Fax: 530.528.4423. Get Directions ». Red Bluff Hours. *Located off of South Main Street on Sister Mary Columba Drive. From I-5, go right on South Main Street to Sister Mary Columba Drive..