This rail-trail, also known as the Lake Wilderness Trail, is a branch off of the Cedar River Trail, leading to Maple Valley and Lake Wilderness. Ultimately King County would like to connect this trail all the way through to the Green River south of Black Diamond (hence the name), but they're not there yet.
The first 3+ miles of this planned regional trail are open, though, with a gravel surface. There are road crossings and underpasses, including some short tunnels, and some suburban stretches.
Length: 3+ miles
Share with: hikers, bicycles, dogs
King County Parks:
Doesn't have it's own web page, though, but is mentioned on the Cedar River Trail web page.
Appears on King County's Regional Trails map.