This trail may be accessible in the winter/spring but would likely require snowshoes, snow travel, and a winter recreation knowledge. Proceed with caution if you tackle this trail when in the winter/spring.
From Oregon Hikers:
Accessed from the bureau of Land Management's Wildwood Recreation Area, the Boulder Ridge Trail rises steeply to join the Plaza Trail, which accesses the high ridges of the Salmon-Huckleberry Wilderness. Late June/early July is a colorful time to do this hike as the forest wildflowers will be out and rhododendrons will be blooming all the way up. Take note that the Wildwood Recreation Area is gated at Highway 26 from mid-fall to early spring. During those months, you will have to park at the Wildwood Recreation Area Winter Trailhead and walk half a mile in to access the trail. This hike can be done as a hike/bike or car shuttle with the Huckleberry Mountain via Bonanza Trail Hike.
After parking either at the trailhead, or right off Highway 26 in winter, head towards the wetland trail, crossing a large wooden bridge over the Salmon River. After the bridge stay on the paved section, continuing towards the wetland trail (See the Cascade Streamwatch Loop Hike). This, short, boardwalk section meanders through a wetland, and a few spurs lead off to beautiful wetland views. After leaving the wetland area at the Boulder Ridge-Wetlands Trail Junction, you will see a sign pointing left to the Boulder Ridge Trail, where this hike really begins.
The Boulder Ridge Trail was constructed in 1981 as a new access link to the Plaza Trail. The north trailhead for that trail, located on private land, has had its easement revoked.
The trail will pass the trailhead sign for the Boulder Ridge Trail #783A, cross a small footbridge over a creek, and then hike up to pass a huge cedar stump. The trail heads up to the left, passing a huge cedar stump. Continue up on a rocky tread and switchback up to cross a gully. The trail heads up under alders and gives a view to Zigzag Mountain. Switchback and traverse, head up a gully, and then switchback up seven times. The trail traverses up a slope, crosses two creeks, and switchbacks at an open viewpoint looking west. Recross one of the creeks and switchback in alder woods. The trail rises and then drops slightly before heading up an old road bed and traverses upward in hemlock forest. The path leaves the road bed and rises on a long traverse on a bear-grass carpet under hemlocks and Douglas-firs. Cross small creek and switchback twice to make a traverse among rhododendrons. A spur leads left to a clifftop viewpoint of Mount Hood. The trail rises to a ridge crest and then keeps below the crest to make a long traverse and round the nose of the ridge in hemlock, Douglas-fir, cedar, bear-grass, rhododendron, salal, and Oregon grape woodland. Now keep along the ridge crest and pass a rocky viewpoint with a couple of manzanita bushes. Below the ridge now, the trail heads gently up. Traverse up and enter the montane zone of noble and silver fir. Reach the Plaza-Boulder Ridge Trail Junction and head right (Going left on the Plaza Trail will take you a long way down the ridge on a disappearing tread until you reach a private property line, where you will have to turn back and retrace your steps).