Henry’s Ridge Natural Area

The 1,240-acre forested Black Diamond Open Space (BDOS) is located two miles north of Black Diamond and six miles south of Maple Valley. This special park contains portions of a protected migratory corridor called the Wildlife Habitat Network. It also contains streams, peat bogs, and wetlands.

King County Parks is actively restoring the health of the forest with periodic stewardship activities such as invasive weed removal, thinnings, and plantings. Prior to public-ownership, portions of the forest in BDOS were clear-cut. King County Parks replanted the forest in 2014. During this lengthy transition, forests can sometimes look a little scruffy. Active forest stewardship increases resilience to droughts, pestilence, and wildfire and makes for better habitat and ecological diversity. BDOS is a Forest Stewardship Council® (license code FSC-C008225) certified working forest.

BDOS straddles two distinct watersheds. The Cedar River Watershed and the Green River Watershed.  Rock Creek, a fish-bearing stream runs through the site which drains to Cedar River and out to Puget Sound. Ravensdale Creek also flows through the site, eventually draining to the Green River which eventually joins Duwamish River and into Elliott Bay. These waters are valuable for cutthroat trout, coho, sockeye, and chinook salmon. The presence of beavers and freshwater mussels are indicators of good water quality.

The largest and most publicly-used portion of BDOS includes 17 miles of trails built over many years for non-motorized uses.