At the end of
the most recent North American glacial era, about 12,000 years ago, the
Midwest was populated with megamammals such as giant ground sloths,
peccaries, and mastodons. The fossils of a number of these creatures have
been found in the Kimmswick Bone Bed near Imperial, Missouri.
Paleontologists theorize that the area once contained mineral springs
and swamps and that many animals became trapped in the mud. One of the
most common bones found in the bone bed are those of the American mastodon
(photo left) that lived from at least 3.75 million to 11,000 years ago. Mastodons are
related to modern elephants and as adults they stood between 8 to 10 feet
high at the shoulder and weighed between 8,000 to 12,000 pounds. The
first recorded report of bones of mastodons and other now-extinct animals in
this area was in the early 1800s. St. Louis Museum owner, Albert C. Koch,
Ph.D., investigated a report of bones weathering out of the banks along Rock
Creek and conducted excavations in 1839. At the turn of the 20th century,
nationwide interest in the site was revived when amateur St. Louis
paleontologist C. W. Beehler excavated several skulls, jaws, teeth, tusks
and other fossils. Railroad tours from St. Louis brought many lay and
professional visitors, particularly during the 1904 World's Fair, to visit
Beehler's wood shack museum near the bone bed.
interest in the site was revived in the 1970s during the construction of
I-55. A movement to save the site from future destruction was organized by
the Mastodon Park Committee. Through the efforts of the committee, local
legislators, private individuals, corporations, and local school children,
and with the help of a federal grant, the Missouri Department of Natural
Resources was able to purchase the 418 acres of land that included the bone
bed in 1976.
Native Americans also had reached present-day Missouri by at least 12,000
years ago. For a brief period at the end of the Pleistocene epoch, the lives
of humans and mastodons intertwined. In 1979, during a Missouri DNR
sponsored excavation, paleontologist Russell W. Graham of the Illinois State
Museum provided the first solid evidence of the coexistence of humans and
mastodons, as a stone "Clovis" type projectile point was found in
association with mastodon bones. This was the first site in eastern North
America where this association was conclusively demonstrated.
museum on the site tells the natural and cultural story of the oldest Native
American site that one can visit in the Missouri State Parks system. A
full-size replica of a mastodon skeleton highlights the exhibits and is part
of a lifescene (photo left) that depicts a Clovis campsite as it may have
appeared 11,000 years ago. Other features include numerous exhibits about
prehistoric animals, Clovis era Native Americans, and the sciences of
paleontology and archeology. An informative slide show runs every half hour
(later starting times for Sundays.) Visitors may take the Wildflower Trail
that begins next to the museum and leads to the site where the bones and
artifacts were found. Although excavations have been closed to protect the
bone bed, an interpretive kiosk explains past excavations. A nominal
admission fee is charged to adults visiting the museum.
Mastodon Park Committee established the Callison Memorial Bird Sanctuary in
1995. The flowers planted in the small area next to the museum provide food
and habitat for butterflies and birds. Nearby benches provide a quiet spot
to view birds attracted to the feeders year-round. The park features 3
hiking trails, shady picnic sites with grills, a playground, and horseshoe
Visiting the Mastodon State Historic Site
grounds are open daily from 8 am to one-half hour after sunset year-round.
December through February, the museum is open Monday, Thursday through
Saturday from 11 am to 4 pm, Sunday from 12 pm to 4 pm and is closed Tuesday
and Wednesday. The remainder of the year, the museum is open Monday through
Saturday from 9 am to 4:30 pm and Sunday from 12 pm to 4:30 pm. The museum
is closed on New Year's Day, Easter, Thanksgiving and Christmas.
There is no fee to visit
the grounds, a nominal fee to visit the museum is charged to visitors 15 and
Directions: Mastodon State Historic Site is located near
Imperial Missouri off of I-55. From Exit 186/Imperial/Kimmswick take
Imperial Main Street west and turn right (north) onto West Outer 55 Road.
Turn left onto Seckman Road to go to the picnic area or continue West Outer
55 Road and turn left
onto Charles J. Becker Drive, which will take you to the museum entrance.
more about the Imperial and Kimmswick
State Historic Site - Official site maintained by the Missouri
Department of Natural Resources.
Mastodon State Historic Site
Limestone Hill Trail
This loop trail shares a
trailhead with Spring Branch Trail located in the picnic
area just to the west of the visitors center. Before the
Limestone Hill Trail splits off it passes by the Bollefer
Springhouse. Use caution when crossing Seckman Road;
vehicles are often fast and frequent. The Limestone Hill
Trail is a steep and rugged hike with challenging slopes and
rough terrain leading you along the base of a limestone
bluff, up a hill through an oak hickory and cedar forest and
across the hilltop with scenic views of Seckman Valley.
There are several benches and overlooks along the trail.
Spring Branch Trail
This trail shares a
trailhead with the Limestone Hill Trail
located in the picnic area just to the west of the visitors
center and offers
a leisurely hike through a portion of the Rock
Creek bottomland. The packed gravel surface is manageable
for wheelchairs and strollers to follow a small stream
flowing from the Bollefer Spring past remains of the
Bollefer springhouse, built in 1837. The trail loops through
a young forest and winds along Rock Creek before returning
to the trailhead.
This trail guides visitors
down a series of stairs to the Kimmswick Bone Bed, where
scientists first discovered evidence that American mastodons
coexisted with humans 12,000 years ago. The trail passes the
Callison Memorial Bird Sanctuary, a wildflower area, crosses
an old limestone quarry, and goes down a limestone bluff and
talus slope to the bone bed. Past the bone bed, the trail
continues to a small foot bridge over a spring that actively
flows after heavy rain. The trail then heads uphill through
a dense oak forest to the limestone bluff and then back to
an intersection that leads visitors back to the museum or to
Callison Memorial Bird Sanctuary.