Do you need a day-use permit for the Obsidian trailhead in the Three Sisters Wilderness?

Yes. Obsidian is one of the limited-entry trailheads in the Central Cascades wilderness permit system, and entering there requires a day-use permit reserved in advance rather than something picked up at the trailhead. It is also among the most in-demand trailheads in the entire system, in the same demand tier as the Devils Lake/South Sister trailhead, so treat popular summer dates as reservations to plan for, not formalities.

The system has two separate permit types, and mixing them up is the classic mistake. A day-use permit covers exactly that: entry at the Obsidian trailhead for a single day. Overnight trips into the wilderness run on a separate Central Cascades overnight permit. If you are backpacking, the overnight permit is what you need; if you are hiking the Obsidian area and out by dark, the day-use permit is the right product.

Why Obsidian specifically runs hot: the trailhead accesses a distinctive volcanic landscape in the Three Sisters high country that has been a special-protection area for years precisely because demand outran its capacity. The quota is the tool keeping it recoverable.

Practical advice: reserve as soon as your date is set, prefer weekdays, and check back for returned permits if your date is gone, since day-use cancellations for even the most popular trailheads reappear regularly right up to the entry date.