Facility Hours

Mastodon State Historic Site

2025-2026 State Holidays

On the following days (actual or observed), staff will not be available and site buildings will be closed: Thanksgiving Day; Nov. 28, 2025; Christmas Eve; Christmas Day; New Year’s Eve; New Year’s Day; Martin Luther King Jr. Day; Lincoln’s Birthday; and Washington's Birthday.

Know Before You Go: Park and Site Status Map

For temporary closures related to weather, stewardship activities and maintenance, as well as temporary trail closures, please visit our Park and Site Status Map.

Historic Site Grounds

8 a.m. to half-hour after sunset, daily, year-round

Museum

March 16 through Nov. 15

Museum closed Monday and Tuesday

9 a.m. to 4:30 p.m. Wednesday through Saturday

Noon to 4:30 p.m. Sunday (closed Easter Sunday)

Nov. 16 through March 15

Museum closed Monday through Wednesday

11 a.m. to 4 p.m. Thursday through Saturday

Noon to 4 p.m. Sunday

Historic Site Office Hours

9 a.m. to 4:30 p.m., Monday through Saturday

Noon to 4:30 p.m., Sunday (closed Easter Sunday)

Please note there will be times when the office is temporarily closed while staff are working on the grounds. The office telephone is monitored for messages during office hours.