C.R.S. § 42-4-1002

(1) Drivers of vehicles proceeding in opposite directions shall pass each other to the right, and, upon roadways having width for not more than one lane of traffic in each direction, each driver shall give to the other at least one-half of the main-traveled portion of the roadway as nearly as possible. (2) A driver shall not pass a bicyclist moving in the same direction and in the same lane when there is oncoming traffic unless the driver can simultaneously: (a) Allow oncoming vehicles at least one-half of the main-traveled portion of the roadway in accordance with subsection (1) of this section; and (b) Allow the bicyclist at least a three-foot separation between the right side of the driver’s vehicle, including all mirrors or other projections, and the left side of the bicyclist at all times. (3) Any person who violates any provision of this section commits a class A traffic infraction.