If you go to Sandstone Ranch early on a December morning after a cold, clear night, moisture rising from St. Vrain Creek may transmute from vapor to solid, skipping the liquid phase. Then, magic happens. Every twig and weed along the creek is bediamonded with hoar frost, and even trash cans sparkle with forests of inch-long frost spires.

The magic melts quickly as the sun rises, but other miracles may happen. Bald eagles, who often nest in large cottonwoods near the creek, may soar overhead. Wild turkeys may strut through the adjacent prairie dog towns. And white-tailed deer may spring across the fields.

Two walking options start at the southeast end of Longmont’s Sandstone Ranch Community Park and Nature Area. A short loop goes down and around the sandstone bluff, and a longer out-and-back hike on the St. Vrain Greenway Trail goes down through the Peschel Open Space.

The loop hike, ¾ mile, begins at the upper parking lot, the highest point on the ranch. We like to start with a short detour on a spur that goes to an overlook where you see St. Vrain Creek and wetlands below and the snow-covered Indian Peaks to the west. Interpretive signs tell the story of Morse Coffin who homesteaded here in 1860, quarried for sandstone and built the handsome home below the bluff.

From here, we start the loop in a clockwise direction on the wide gravel road that’s closed to traffic. As you descend, look for clam and other fossils embedded in the boulders beside the trail. Continuing down, you pass the old quarry on your right and a prairie dog town to the left. A fence separates Sandstone Ranch from land to the east that’s closed to the public. White-crowned sparrows, house finches, juncos and other brush-loving birds sometimes hang out in the hawthorns and mountain maples here.

On reaching the flats the trail bends westward, with prairie dog colonies both left and right. Cottontails use the prairie dog burrows; barn and great horned owls sometimes nest on the cliffs; Canada and cackling geese patrol the grounds and geese and ducks swim in the small pond below the Coffin House.When the trail forks, turn right and walk past the house and outbuildings and up the trail adjacent to the paved road to close the loop. The complex also includes a barn, a spring house and a toolshed.

The section of the St. Vrain Greenway Trail through the Peschel Open Space starts at a small parking area at the bottom of the hill near the Coffin House. Walk down the road past the house and small pond onto the paved St. Vrain Greenway Trail and cross a bridge over Spring Gulch. Part of the area south of the trail is still being mined for gravel, and some areas are closed to the public.

A second bridge spans St. Vrain Creek. At the end of November, hundreds of mallards and white-cheeked geese thronged together upstream from the bridge. This seems to be a popular gathering place, as we’ve observed quacklings of ducks and cacklings of geese here many times over the years. Also watch for muskrats, mink and beavers in the riparian areas.

Continue past several lakes often filled with waterfowl. Red-winged blackbirds usually create cacophony in the cattail marshes and kingfishers and great blue herons often fish in the creek. In 1.7 miles, you come to the St. Vrain Greenway parking lot on Weld County Road 1. If you don’t want to retrace your route, you can spot one car here and another at Sandstone and make a one-way, downhill hike.

If you’re really feeling energetic, the St. Vrain Greenway Trail continues west all the way to Golden Ponds (about 8 miles), with numerous laterals and connections along the way.

Directions: From Longmont, drive east on Ken Pratt Boulevard to the sign for Sandstone Ranch Park about 1 mile east of WCR 1 (also called East County Line Road). At the traffic light, turn south on Sandstone Drive and continue past the ball fields and picnic areas. When the road forks, turn left and park at the upper parking lot and trailhead for the loop hike. Continue straight ahead for the lower parking lot and Greenway Trail.

Ruth Carol and Glenn Cushman are the authors of “Boulder Hiking Trails,” available on Amazon.