A highlight of Louisville's trail system is the Coal Creek Regional Trail which runs east to west along Coal Creek in the southern part of Louisville. The Coal Creek Regional Trail is a continuous eight-mile, mostly soft-surface trail that currently runs from McCaslin Boulevard in Superior through Louisville to 120th Street in Lafayette. A joint effort between the cities of Louisville, Lafayette, Superior and Boulder County, the trail will eventually tie into the City of Boulder and Town of Erie trail systems as well as link to the Rock Creek Trail system and the City and County of Broomfield. Louisville is fortunate to have direct access to one of Boulder County's most well-developed and beautiful regional trail systems.
From 287, travel to Louisville. Turn West on Highway 42/Empire Road (East is Exempla Circle). Go for about 1.5 miles, and on the North side is the Aquarius Trailhead parking lot (just West of the Louisville Cemetary). It's at the top of the hill.
http://www.tripleblaze.com/trail.php?c=3&i=495