Starting from the eastern end of the Cobalt Trail at the Boulder Valley Ranch Trailhead, hike over gently descending, open terrain paralleling Longhorn Road. The fields here are grass covered and feel very bucolic. The trail is mostly singletrack, but it sometimes widens as it arrives at gates. Looking east, you'll see views of pointy Haystack Mountain and Boulder Reservoir in the distance.
Eventually the trail veers away from the road and skirts several scattered prairie dog communities. On the hillside to the south, you'll see the huge concrete foundations for an old mill that once operated here. Next, contour around the side of a low butte punctuated by layered rocks that jut out. This part of the trail is high enough to allow good views south of the distant flatirons and Bear Peak.
The Cobalt Trail ends at a gate and then dumps out onto the wide, road-like terminus of Eagle Trail
. To reach the informal trailhead and parking area, head west another hundred feet on the Eagle Trail
and pass through another gate into the parking area.
Eagles, northern harriers, red-tailed hawks, deer, coyotes, prairie dogs, rattlesnakes, bull snakes.