The pass is located in southwestern Clear Creek County, in the Front Range west of Denver and south of Georgetown.

The pass was named in 1953 for Byron Guanella, a road supervisor and commissioner in Clear Creek County for nearly 50 years.

The pass provides a route between Georgetown in the valley of Clear Creek to the north and Grant in the valley of Geneva Creek, a tributary of the North Fork South Platte River, to the south.

[1] The entire route from Georgetown to U.S. Highway 285 is paved,[2] but is not maintained in the winter and often closed seasonally after the first heavy snow.

The Geneva Basin Ski Area which existed from 1963 to 1984 was located just a few miles south of the pass summit.