Walnut Canyon National Monument is open daily from 9:00 a.m. until 5:00 p.m. MST. There is no access to the canyon, visitor center, park trails and viewpoints when the park is closed.
The Island Rail - is open daily from 9:00 a.m. - 4:00 p.m. Hikers must start the Island Trail before 4:00 p.m.
The Rim Trail - is open daily from 9:00 a.m. - 4:30 p.m. Hikers must start the Rim trail by 4:30 p.m.
Hikers must begin the trails by their posted closing times, and complete the trails before the park's entrance gate is closed at 4:30 p.m.
The park's visitor center, trails and viewpoints are open year-round, except for an early closure at 1:00 p.m. on Thanksgiving, and full closures on December 25th and January 1st. During holiday closures, there is no access to the canyon, visitor center, park trails and viewpoints.
NOTE: Most of Arizona does not observe Daylight Savings Time. The state is on Mountain Standard Time year-round.