This one's from the Mineral Belt Trail in Leadville, Colorado. Along this 11 mile loop there are numerous descriptive markers, awesome views of the Mosquito and Sawatch ranges, and remnants of mining activity. Half of the length of the trail winds through the historic Leadville Mining District where trail-side plaques tell of mining, exploration and settlement of the Leadville area in the 19th century. Much of the trail winds through aspen and conifer forests, providing a near-wilderness experience unlike any other paved bicycle trail I've seen. More information can be found here.