🌤 Weather at Mastodon State Historic Site by season
| Spring | Summer | Fall | Winter |
|---|---|---|---|
| 34–76 °F | 63–88 °F | 35–81 °F | 22–46 °F |
Each range runs from the coldest monthly average low to the warmest monthly average high in that season (1991-2020 climate normals), measured at Festus, 10 mi away, elevation 600 ft. Conditions at the park can differ from the station, especially where elevation differs — check a forecast before you go.
Mastodon State Historic Site is a public state park in Missouri near Imperial. Spanning 431 acres and established in 1976, this park offers a peaceful retreat into nature for visitors of all ages.
Quick Facts
| State | Missouri |
| Nearest City | Imperial |
| Park Size | 431 acres |
| Established | 1976 |
| Google Rating | ⭐ 4.5/5 (400 reviews) |
Location & Getting There
Mastodon State Historic Site is located near Imperial, Missouri. The park’s coordinates are 38.3792, -90.3947.
Things to Do
This is the place where North America first proved that humans and mastodons met. In 1979, paleontologist Russell W. Graham found a stone Clovis spear point lying in direct association with mastodon bones in the Kimmswick Bone Bed — the first site in eastern North America where that coexistence was conclusively demonstrated. The bone bed itself, dug since 1839 and listed on the National Register in 1987, is now safely reburied for future generations; the half-mile Wildflower Trail takes you down the stairs to the site, past the Callison Memorial Bird Sanctuary.
The museum tells the story with a full mastodon skeleton replica at its center, artifact exhibits and a 15-minute film shown roughly every hour. Outside, two more trails round out the visit: the easy, accessible 0.8-mile Spring Branch Trail along Rock Creek past the 1937 Bollefer spring house, and the rugged 2-mile Limestone Hill Trail loop (budget about two hours). In summer, Rock Creek itself is the local secret — officially “a popular place for wading.”
Best Time to Visit
The grounds are open daily year-round, 8 a.m. until a half hour after sunset — but the museum runs on a schedule worth checking: March 16 through November 15 it opens Wednesday–Saturday 9–4:30 and Sunday from noon, closed Monday and Tuesday; in winter it shrinks to Thursday–Sunday. Plan a Wednesday-through-Sunday visit if the skeleton is the point of the trip. This fall is a good moment: the site celebrates its 50th anniversary on September 5, 2026, and hosts Archaeology Day — with atlatl spear-thrower demonstrations — on September 26.
Visitor Tips
The “ticket” question has a simple answer: you pay at the museum door, not the gate. Museum admission is $4 for ages 13 and up, free for kids 12 and under — as of August 2026; the trails, picnic areas and playground list no entrance fee. There is no campground here (only a special-use area for organized youth groups), and pets are welcome on the grounds on a leash, but not inside the museum.
The entrance sits directly off I-55 at Imperial, roughly 20 miles south of downtown St. Louis — figure about half an hour’s drive. The shady picnic sites have grills, and the 80-person shelter rents for $45 a day. Park office: 636-464-2976.
Fees, hours and event dates verified against mostateparks.com on August 30, 2026. Hours change seasonally — confirm before you travel.
Explore More Missouri State Parks
Mastodon State Historic Site is one of many outstanding state parks in Missouri. Discover more parks in our Best State Parks in Missouri guide, or use our Park Finder to search by activity, location, or features.
Wildlife & Nature
Mastodon SHS — preserves the Kimmswick Bone Bed, where mastodon bones and Clovis points were found together — providing definitive proof that humans hunted mastodons in North America. The park’s museum, forest, and creek support white-tailed deer, wild turkeys, and songbirds.
Nearby Attractions
Imperial — adjacent. St. Louis — 20 miles north. Jefferson Barracks — 10 miles north. Gov. Dunklin’s Grave SHS — 5 miles south.
More parks in Missouri: Sandy Creek Covered Bridge State Historic Site and Route 66 State Park. See the full Missouri state parks guide.
🐾 Dogs & Pets at Mastodon State Historic Site
- Pets allowed? statewide rule
- Responsible pet owners and their pets are welcome in Missouri state parks and historic sites, with pets leashed and under control.
- Leash rule statewide rule
- Leash not longer than 10 feet required at all times; portable fences and shock collars do not satisfy the requirement.
- Beaches & swim areas statewide rule
- Pets are not allowed in public swimming areas or on beaches.
- Cabins & lodging statewide rule
- The 'Cabins for Canines' program opens about 30% of lodging units to dogs (max two dogs per unit) at roughly 15 participating parks including Lake of the Ozarks, Bennett Spring, Echo Bluff and Roaring River; per-dog per-night fee varies by unit type.
- Pet fees statewide rule
- No day-use pet fee; Cabins for Canines charges a per-dog, per-night lodging fee (varies by unit).
- Statewide exceptions statewide rule
- Maximum two dogs per campsite; pets not allowed inside any park building.
Are dogs allowed at Mastodon State Historic Site?
Responsible pet owners and their pets are welcome in Missouri state parks and historic sites, with pets leashed and under control. Individual parks can post stricter rules — check signage on arrival.
Rules verified July 2026 via mostateparks.com. More: Missouri state parks guide · Dog rules in all 50 states compared
Park Location
Plan your gear for Mastodon State Historic Site
From our editorial guides, matched to this park’s activities:
