May Nature Walk: Maddie’s Bridge and Beyond

"Civilization exists by geological consent subject to change without notice." This quote from historian Will Durant was a favorite saying of Madeleyne Bridge. It's inscribed on a plaque mounted on a stone to the left of the bridge named in her memory at Heil Ranch. Maddie and her late husband Ray were hikers and Boulder environmental activists for many years.

Maddie's Bridge over Plumely Creek was originally built in 1999 but was severely damaged "without notice" in the 2020 Calwood fire and had to be removed. The Longmont Open Space Department loaned Heil Ranch a strong, sturdy bridge that was placed upstream. Then, this spring Maddie's Bridge was rebuilt and opened to the public in early May, and the loaner bridge was returned to Longmont.

Maddie's Bridge (near the main parking and picnic area) serves as a gateway to two lovely trails — Lichen Loop and Grindstone Quarry — that are regenerating after the Calwood Fire. Charred ponderosa pines and invasive mullein bear stark witness to that fierce fire that burned 5,000 acres in five hours. Following the fire, most of Heil Ranch was closed to the public until last year while the Boulder County Open Space Department undertook extensive restoration. Throughout the forest you’ll notice many mesh "tree tubes" protecting ponderosa seedlings, many of which are now over a foot tall.

Almost three years have passed since the fire. Golden banners, yellow parsleys, blue chiming bells, and white locoweeds and sand lilies are reclaiming the scorched land, and greener-than-before grass covers the blackened soil. After crossing Maddie's Bridge, the trail goes uphill a short distance and forks with the Lichen Loop heading straight and the Grindstone Quarry Trail branching to the right.

Going in a counter-clockwise direction, the 1.3- mile Lichen Loop continues uphill to the ponderosa forest before leveling out and then descending through flower-filled meadows. In the past we’ve encountered wild turkey flocks, mule deer herds, and Abert's squirrels on this route. And, of course, there are multi-colored rocks covered with green, gold, orange, and chartreuse lichens. Be sure to take the short detour up to the old kiln where crushed limestone was converted to quicklime. The 1.4-mile Grindstone Quarry Trail heads up to a viewpoint of nearby ridges and of Bear Peak to the south before dropping to a meadow. As you traverse the meadow, watch for an unmarked spur to the left that leads to the quarry. Peter Haldi, an early postmaster for the town of Altona, established thequarry in the early 1900s to provide grinding-wheel stones for sharpening metal tools.

From the quarry you can either retrace your route back, or you can continue down to a lower parking lot and connect to other trails. Or, you can spot a second car at the lower lot for a one-way, mostly downhill hike of about two miles. The network of trails at the Heil Ranch Open Space allows you to make various connections and longer loops. You can explore a variety of terrains and see historical sites, such as the Altona School. Check "Heil Valley Ranch trail map" online for ideas. Also, check online for trail closures, especially after all the recent rains. Bikes are allowed only on designated trails, and to protect wildlife, dogs are not permitted.

To reach Heil Ranch, take U.S 36. to Left Hand Canyon and turn west. In a short distance turn right onto Geer Canyon Road that goes to the Main Trailhead parking and picnic area.

Ruth Carol and Glenn Cushman are the authors of "Boulder Hiking Trails," available from Amazon.

Sign up for email newsletters