Mt. Thielsen Trailhead / Sno-Park Diamond Lake, Southern Oregon Diamond Lake, Oregon Mt. Thielsen Trailhead / Sno-ParkWebsite Cross-Country Skiiing available in winter. Provides access to: Mt. Thielsen Trail #1456 Pacific Crest National Scenic Trail #2000 Spruce Ridge Trail #1458 Amenities No drinking water Vault toilet No garbage disposal – Please pack it out Oregon Department of Transportation Sno-Park Information