In July and August all the roads, trails, and visitor centers are open, and the Snake River's float season is in full swing. To have access to most services without the crowds, plan a trip in late May, June, or September. Lower rates and smaller crowds can be found in spring and fall, but some services and roads are limited. Grand Teton Lodge Company, the park's major concessionaire, winds down its activities in late September, and most of Teton Park Road closes from November through April. In spring and fall, the road is open to pedestrians, cyclists, and in-line skaters; in winter, it’s transformed into a cross-country ski trail.

Towns outside the park rev up in winter. Teton Village and Jackson both buzz with the energy of Snow King Resort and Jackson Hole Mountain Resort, the former conveniently in town, the latter an international skiing hot spot 13 miles from Jackson. (Prices rise for the peak winter season.) U.S. Highway 26/191/89 stays open all winter.