Turquoise Lake
This is a very pretty loop on Route 9C around a high alpine lake just west of Leadville. The 15-mile loop has 1,300' feet of climb on a quiet road. Park at the Maid of Erin picnic area or one of the several campgrounds around the lake.
Add 8 miles and 500' of climb round trip by parking in Leadville across from the Safeway on US 24 and riding out E. Mountain View Dr. Turn right on Turquoise Lake Rd (route 9) at around 3 miles, bear right at the Y intersection and then turn left on 9 across the tracks to the Turquoise Lake loop road.
Or ride from Breckenridge to Copper and over Fremont Pass to Leadville, around the lake and back for a challenging 100 mile Century ride!
The interactive map linked on the right shows the full route from Leadville.