Alan Thiesen Trail

Well known and loved by locals around Alta Sierra, this trail loops through a small nature preserve, Adam Ryan Preserve, on a hill with a park-like forest, small meadows, and some nice views. It’s worth a trip to discover and enjoy.

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Map Map & Summary Description Google Earth

Place: Alta Sierra area of Grass Valley, CA

Season: Year around

Land: Conservation and trail easements on nearly 40 acres of private land

Trail signs: Bear Yuba Land Trust signs

Length: Main loop trail: 1 mile loop

Altitude change: 160 feet

Difficulty: Easy

Trail surface: Native soil

Environment: Mixed conifers and deciduous trees.

Rules: Foot and bike only. Dogs on leash. No motorized vehicles. Stay on trails.

Trailheads: The main trailhead, with parking for several cars, is located at the intersection of Dog Bar Road and Alta Sierra Drive. From Highway 49 in Grass Valley, take the McKnight Way exit. From East McKnight Way go 2 miles south on La Barr Meadows Road, stay left on Dog Bar Road and go another 1.8 miles to the intersection of Alta Sierra Drive. (N39.14994 W121.03604)

There are two alternative trailheads:

  1. Hangtree Road. Less than 150 yards farther south along Dog Bar Road from the main trailhead, with parking on the road shoulder opposite the intersection of Dog Bar and Rattlesnake roads. Hangtree Road is a private lane on the west side of Dog Bar. Find the trail entrance on your right, about 50 feet up the lane. (N39.14930 W121.03487)
  2. Alta Sierra Drive. Go about 1/3 mile west on Alta Sierra Drive from the main trailhead and look on the left. (N39.14711 W121.04120) Limited parking options.

Trail tips: To do the full loop from the main trailhead, walk about 50 feet into the preserve and go left or right. (The wide path you see going straight ahead is a shortcut to an upper portion of the trail.) The forest on the upper and south-facing portions of the preserve is unusually open and park-like, with some large old ponderosa pines, tall oaks, and a grand madrone tree near the top. You will catch occasional views of the Alta Sierra Country Club fairways, the surrounding hills and residential neighborhoods. Up on the northwest shoulder of the hill, there is a short section of the Rattlesnake Canal where you will see water running. Please do not follow the canal toward the golf course or follow the service road to the bottom of the hill. The return path along the forested north side of the preserve goes through vast patches of non-native blackberry. It is cool and shady here in the afternoon.

This trail is a joint project of the Alta Sierra Property Owners Association and the Bear Yuba Land Trust. The trails are well maintained. The conservation and trail easements that made this preserve possible were a gift of Alta Brewer, daughter of early area rancher George Brewer. The trail is named after her husband, and the preserve after her son.

Side Trip: While you’re in the area, you might enjoy a visit to nearby Mathis Pond, on a 1.75 acre preserve owned by Bear Yuba Land Trust. Here you will find a large, spring-fed pond that acts as a home and way station for waterfowl. Improvements include an informational kiosk and graveled trail. This was the first property acquired by the land trust for permanent preservation, shortly after its formation in 1992. It is named for the donors, Ray and Helen Mathis. To reach Mathis Pond, go about ¼ mile south on Dog Bar Road from Alta Sierra Drive. There is parking along the road shoulder just north of Carrie Drive.

Visit Adam Ryan Preserve
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