August: Wheeler Peak's summit trail is snow-free, the 4,000-year-old bristlecone pines are reachable, and August's dark, moonless skies are among the best in the country.
September: Aspens turn gold along Wheeler Peak Scenic Drive, days stay mild, and the high trails remain open before the first snow.
Permits and reservations
No entry reservation. Lehman Caves is visited only on ranger tours.
Lehman Caves tour tickets: Everyone, including children, needs a ticket to visit the cave. Reserve on Recreation.gov (up to 30 days ahead), or buy a walk-up ticket at the visitor center when it opens the day of the tour. Walk-up tickets often sell out within an hour.