Picture Rock Trail

Picture Rock is the trail that links Lyons to Heil Valley Ranch, 5.2 miles of rolling singletrack through meadow and ponderosa along the base of the foothills, past the ruins of the Cardinal Mine and an old sandstone quarry where the lichen-patterned Lyons sandstone that gives the trail its name was cut. It is a Boulder County open-space trail with no dogs allowed, like the rest of Heil Valley Ranch, and popular enough with mountain bikers that hikers pick their hours.

From the Picture Rock trailhead south of Lyons, the trail climbs gently through meadow and scrub oak with the hogback to the east, passing the quarry site where the flat sandstone slabs are stacked beside the trail, then enters ponderosa and rolls south along the foothills.

The Cardinal Mine ruins, a stone foundation and tailings from a gold operation, come in the middle miles. The trail continues south to the Wild Turkey and Wapiti trail junctions in Heil Valley Ranch, 5.2 miles from Lyons, which makes a point-to-point with a car at Heil's main trailhead or a 10.4-mile round trip. The 700 feet of gain is spread over the whole length; the out-and-back to the mine is the shorter option.

The Picture Rock trailhead is on Red Gulch Road off Colorado 7 at the south edge of Lyons, a Boulder County lot with 25 car spaces, a restroom, and horse-trailer parking that fills by 8 AM on weekends in spring and fall. The Heil Valley Ranch main trailhead, for the point-to-point, is on Geer Canyon Drive off Lefthand Canyon Drive. Both are free, open sunrise to sunset. No permit.

Dogs are prohibited on Picture Rock, as on every trail in Heil Valley Ranch, to protect the elk herd and other wildlife, which is why the record shows no dogs; stay on the trail, which is required across the whole property. The distance is why the trail is listed for older kids; the walk to the quarry is fine for any. Mountain bikers ride the trail in numbers and the county asks them to yield, which they mostly do. Rattlesnakes live in the rocks. Carry water. Lyons has restaurants at the trailhead. The Boulder hikes page has the rest of the county's open space.