Petrified Forest is the only US national park that I-40 actually passes through, the 28-mile main park road begins at I-40 Exit 311 (Painted Desert / North Entrance) and ends at US-180 near Holbrook (South Entrance). Visitors driving cross-country can do the entire park as a 1.5-hour detour without backtracking. The park protects one of the largest concentrations of petrified wood on earth (220-million-year-old Late Triassic logs replaced cell-by-cell with quartz) plus the multicolored badlands of the Painted Desert at the north end and significant Ancestral Puebloan archaeological sites in the middle. The park has no entrance fee station, you pay at one of two visitor centers and receive a tag visible on your dashboard. Park gates close at posted hours; never stop overnight unless camping in a permitted backcountry area.
- Only US national park that I-40 directly traverses
- Largest concentration of petrified wood on earth (~220 million years old)
- Includes the Painted Desert badlands and Newspaper Rock petroglyphs
- Park has set hours, gates close (typically 5 PM in winter, 7 PM in summer)
- No food, lodging, or fuel inside the park