If you want to backpack or even day hike in the heart of the Three Sisters Wilderness, the most important thing to understand is the permit system. Since 2021 the most popular trailheads in Oregon's Central Cascades have used a limited-entry permit to control crowding, and the rules trip up first-time visitors every summer. Here is exactly how it works and how to land a permit for the trails you want.
Why Permits Exist
The Three Sisters Wilderness sits a short drive from Bend and absorbs enormous use. Trails like Green Lakes, Obsidian, and the route toward South Sister were being loved to death. The Forest Service responded with a quota system administered through Recreation.gov, capping how many people start at each entry point per day. The goal is to protect fragile alpine meadows while keeping access fair.
Which Permits You Need
There are two layers to understand. First, the Central Cascades Wilderness Permit controls trailhead entry during the quota season. Second, a Northwest Forest Pass or interagency pass is required to park at most trailheads year round. You may need both. The limited-entry permit applies to:
- Overnight trips at nearly all Three Sisters trailheads during the season
- Day use at a handful of the busiest trailheads, including Green Lakes, Devils Lake (South Sister), Obsidian, and Tam McArthur Rim
- The Obsidian Limited Entry Area, which has had its own day quota for years
When the Season Runs
The quota period typically runs from the last Friday in June through the last Friday in October. Before and after those dates you can hike using a free, self-issued wilderness permit at the trailhead, though snow and weather become real factors at the shoulders of the season.
How and When to Book
Permits are released in two waves on Recreation.gov. A large block opens in early spring for the entire season, and a rolling window releases additional permits seven days in advance. Overnight permits cost a small per-person reservation fee plus the booking fee, and they let you exit from a different trailhead than you entered, which is ideal for loop trips. Popular dates for South Sister and Green Lakes can sell out within minutes of release, so set a reminder and have your dates and party size ready.
Tips to Actually Get One
A few strategies dramatically improve your odds:
- Be online the instant the 10 a.m. window opens on release days
- Target less famous trailheads like Pole Creek or Scott Pass, then connect to the interior on foot
- Aim for weekday entry dates, which clear far less competition than weekends
- Use the 7-day rolling release if you missed the spring block; cancellations also reappear
Once you have your permit, the interior opens up. Our 4-day Three Sisters Wilderness backpacking itinerary shows how to chain Green Lakes, the Chambers Lakes, Camp Lake, and Obsidian Falls into one loop, and notes which entry points pair best with the permit system.
Rules to Follow Once You Have It
Print or download your permit and carry it. Camp only in designated or durable sites, keep stock and campfires within posted limits, and store food properly given the area's curious wildlife. The whole permit effort exists to keep these basins pristine, so practicing Leave No Trace is part of the deal.
The permit process feels intimidating the first time, but once you understand the two waves and pick a realistic entry point, the Three Sisters Wilderness is well within reach for a summer trip.
