Tam McArthur Rim Trail Hiking Guide
Tam McArthur Rim rises like a wall above Three Creek Lake south of Sisters, and the trail up it delivers one of the broadest views in the Three Sisters Wilderness for a moderate half-day. You climb out of the forest on switchbacks, then walk the open rim toward Broken Top with the lake far below. Here is what to know about the permit, the road and the season.
Permit: From June 15 to October 15 day hikers need a Central Cascades Wilderness day-use permit for the Tam McArthur Rim Trailhead, reserved through Recreation.gov or 1-877-444-6777 for a $1 per-person reservation fee; overnight trips need an overnight permit ($6 per group of up to 12). The Forest Service trailhead page lists no parking fee. In winter the road is gated and the nearby Three Creek Sno-Parks require an Oregon Sno-Park permit from November 1 through April 30.
Switchbacks to the Rim
Trail #4078 leaves the trailhead by Three Creek Lake and enters the Three Sisters Wilderness almost at once. AllTrails maps the out-and-back at 5.4 miles with 1,266 feet of gain, rated moderate and averaging just under three hours, and describes a winding singletrack that switchbacks above the trees before topping out on the rim. From there the route follows the edge toward Broken Top, with the lake and its forested basin below. No agency mileage is published for this route, so the AllTrails figures are the ones used here.
Permit Season and Booking
Tam McArthur Rim is one of the trailheads where day hikers, not just backpackers, need a Central Cascades Wilderness permit from June 15 to October 15. Reservations run on a rolling window: roughly two-fifths of a date's quota is released on Recreation.gov ten days out, the remainder 48 hours out, both at 7 in the morning Pacific time. You can also book by phone, and the only charge is a $1 reservation fee per hiker. Outside that window the quota doesn't apply, though you are still in designated wilderness with its rules.
Three Creek Lake and the Road In
The Forest Service puts the trailhead 16.4 miles south of Sisters on Forest Road 16. Three Creek Lake, at 6,550 feet, sits in a glacial cirque beneath the rim; motorboats are banned, and a small store on the east shore rents boats. There is no drinking water at the trailhead. Road 16 isn't plowed: the Forest Service gates it for winter after snow, just beyond Upper Three Creek Sno-Park, and on the day this page was checked it listed the road as open.
Dogs and Wilderness Rules
Dogs can hike the rim; this trail is not one of the Three Sisters routes with a summer leash order, but keep them under control around other hikers and wildlife. Groups are limited to 12 people, campfires are prohibited above 5,700 feet, and bikes and drones are not allowed anywhere in the wilderness. Pack out everything; there are no facilities beyond the trailhead.
Hiking tips for Tam McArthur Rim Trail
- Book the day-use permit early for summer weekends; the trailhead has a quota.
- Start early on summer weekends; the trailhead quota still brings a steady stream of hikers.
- Carry all your water; there is none at the trailhead.
- Stay back from the rim edge, especially with kids and dogs.
- Check the Forest Service road status for Road 16 before driving up in late fall.
Nearby trails to explore
- Green Lakes Trail (Three Sisters)
- Tumalo Mountain Trail
- Misery Ridge Trail (Smith Rock)
Hike this trail with TrailMates
Tam McArthur Rim is a big-view half day that is easier to plan with a group on one permit reservation. Use TrailMates to find Bend and Sisters hikers heading for Three Creek Lake. Download TrailMates on the App Store or Google Play to join a group.