August: The high trails finally melt out, turquoise lakes glow with glacial flour, and the park stays among the least crowded in the Lower 48.
Permits and reservations
No entry reservation. Overnight backcountry trips need a reserved permit.
Backcountry permits: In 2026 the early-access lottery ran Mar 2–13 (results Mar 20), winners booked Mar 24–Apr 21, and the general on-sale opened Apr 29 at 7 a.m. PT. Reserve at least 2 days before your trip.