Headwaters Campground at Flagg Ranch

October offers the best shot at a last-minute site in Grand Teton — 36.8% of that month's 2,185 reservations were made within a week of arrival, the highest rate of any month. May is the next-best window at 27.8% last-minute across 8,817 reservations, and Jenny Lake specifically shows 47.1% last-minute availability in May. July is the hardest month across the board, with 19.0% of reservations locked in 6+ months ahead and only 16.9% left to last-minute bookers across 24,449 total bookings.

Grand Teton does not operate a comprehensive free shuttle system like Zion, so a personal vehicle is the practical way to move between campgrounds, trailheads, and the Moose Visitor Center. The park's main corridor along Teton Park Road and Highway 89/191 is accessible to most vehicles, though Colter Bay RV Park's 55-foot limit and Signal Mountain's 32-foot cap mean large rigs need to plan routes carefully. Boats accessing Colter Bay Marina End Ties should note the 30-foot vessel limit at that specific location.

Grand Teton charges $35 per vehicle for a 7-day entrance pass. Nightly camping rates vary by campground and site type — hookup sites at Colter Bay RV Park and electric sites elsewhere carry higher fees than standard non-electric sites. The America the Beautiful annual pass ($80) covers the entrance fee for the pass year and is worth it if you're visiting multiple federal lands. Note that camping fees are paid separately and are not covered by the pass.

Stay limits vary by campground: Jenny Lake enforces a strict 7-night maximum while most others allow 14 nights — a meaningful difference for longer trips. Cell service is limited throughout the park, particularly at Headwaters Campground at Flagg Ranch, so download offline maps before arrival. Jackson, Wyoming is the nearest full-service town for groceries and supplies, though Colter Bay Village has an on-site grocery store and restaurant that reduces the need for frequent supply runs during a Colter Bay-based stay.