Morgul-Bismark Loop

The Morgul-Bismark is a 13.1-mile circuit of public roads south of Boulder: east from Colorado 93 on Colorado 170 (Marshall Road or Marshall Drive), south on McCaslin Boulevard through Superior, west on Colorado 128 and north on Colorado 93. Much of it rolls through open grassland; westbound Colorado 128 faces the Flatirons, the Eldorado Canyon gap and wind turbines.

Its signature is the Wall, a mile-long climb on McCaslin Boulevard that steepens until it flattens at Colorado 128. Around Superior the prairie the races crossed is built over, so frames need care. The top of the Wall and about half of the Colorado 128 leg are in Jefferson County.

The Red Zinger and Coors International bicycle classics raced the loop from 1975 to 1988; men climbed the Wall eight times, women four.

Filming that may significantly affect traffic on the state highways outside town limits (Colorado 93 and the western parts of Colorado 170 and 128) needs a Colorado State Patrol special event permit; apply early. Closing McCaslin Boulevard, a Town of Superior street, needs the Town’s Street Obstruction Permit, received by Public Works at least 14 days ahead.