During the summer months, Monument Valley is open from 07:00 AM to 07:00 PM. Note: the last entry time is 04:30 PM. In the winter months, Monument Valley is open from 08:00 AM to 05:00 PM. Note: the last entry time is 02:30 PM. Monument Valley is closed on Thanksgiving Day (4th Thursday in November), during Christmas, and on New Year's Day. Always check the navajonationparks.org website for current changes.