Why we love it: Playful prairie dogs, skittish mule deer, and red-tailed hawks soaring above open grasslands and sandstone bluffs, all next door to the hip town of Lyons.
When to go: After the weather has been dry for a couple of weeks. Otherwise, you’ll have to squelch through deep and gooey mud.
Open to hikers and bikers, Boulder County’s Hall Ranch offers rolling grasslands, shady stretches of ponderosa-juniper forest, sandstone bluffs, and smooth granite boulders to stretch out and take a nap on. In other words, most outdoorsy types will be pleased. The 9.5-mile Bitterbrush-Nelson-Nighthawk Loop is one of my favorite hikes because it’s long enough to truly escape, but short enough to complete in half a day.
I prefer to follow this loop counterclockwise, beginning with the 3.7-mile-long (one way) Bitterbrush Trail, which begins at the upper parking lot. The route meanders below blocky sandstone buttes and crosses dense shrublands before climbing steeply through the gray granite. The gap in time between these 1.7-billion-year-old boulders and the lowest sandstone layers is equivalent to one-quarter of Earth’s history. (Wow!)
About two miles from the trailhead, you break out of the trees onto a north-facing slope, where you’ll be treated to beautiful views of the North Saint Vrain River canyon. Here, a colony of black-tailed prairie dogs chirp happily away, warning people not to get too close to their burrows. This is the best spot to turn around if you don’t have enough time to complete the loop or have minions in tow.
As you descend to the junction with the Antelope Trail, keep an eye out for hawks, golden eagles, rabbits, and a second prairie dog colony just west of the path. When you reach the Nelson Loop, turn left onto the south fork, which passes the old Nelson Ranch House (built about 1918). A quarter mile farther, at the next trail junction, cyclists must complete the Nelson Loop and retrace the Bitterbrush Trail, whereas hikers have the option of returning to the trailhead via the peaceful, 4.7-mile-long Nighthawk Trail, which features the best views of the high peaks in Rocky Mountain National Park. I often see mule deer in this area, and it’s also possible to catch a glimpse of a bighorn sheep or large predators, including bobcats, coyotes, and mountain lions.
After dropping through thick stands of ponderosas and crossing more open grasslands, the route climbs up and over a ridge, then drops into a small canyon before winding back toward the east and the parking lots.
Getting there: From Denver take I-25 North to U.S. 36 West, and follow this to the junction with SR 66. Turn left here, staying on U.S. 36 through the town of Lyons. At the junction with CO-7, turn left and proceed 1.5 miles to the signed entrance on the right.