Meramec State Park is located near Sullivan, Missouri

Sullivan, Missouri

Sullivan is a city that straddles the border of Franklin County and Crawford County in the U.S. state of Missouri. The population was 6,351 at the 2000 census. Stephen Sullivan founded the city in the late 1850s and cleared brush, which facilitated the building of the railway depot there, and the...

, about 60 miles from St. Louis

St. Louis, Missouri

St. Louis is an independent city on the eastern border of Missouri, United States. With a population of 319,294, it was the 58th-largest U.S. city at the 2010 U.S. Census. The Greater St...

, along the Meramec River. The park has diverse ecosystems such as hardwood forests, and glade

Glade (geography)

A glade or clearing is an open area within a woodland. Glades are often grassy meadows under the canopy of deciduous trees such as red alder or quaking aspen in western North America. They also represent openings in forests where local conditions such as avalanches, poor soils, or fire damage have...

s. There are over 40 cave

Cave

A cave or cavern is a natural underground space large enough for a human to enter. The term applies to natural cavities some part of which is in total darkness. The word cave also includes smaller spaces like rock shelters, sea caves, and grottos.Speleology is the science of exploration and study...

s located throughout the park, the geology of which is a mixture of limestone

Limestone

Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

 and dolomite

Dolomite

Dolomite is a carbonate mineral composed of calcium magnesium carbonate CaMg2. The term is also used to describe the sedimentary carbonate rock dolostone....

. The most famous is Fisher Cave, located near the campgrounds.

In the late 1970s, as part of the Meramec Basin Project, the U.S. Army Corps of Engineers began work on a dam in the park to impound the river. The resulting reservoir would have permanently flooded much of the park and imperiled many different species, including the endangered Indiana bat

Indiana bat

The Indiana bat is a medium-sized mouse-eared bat native to North America. It lives primarily in eastern and midwestern states and in parts of the south of the United States. The Indiana bat is gray, black, or chestnut in colour and is 1.2–2 inches and weighs about 1/4 an ounce...

. However, in response to direct citizen action against the dam, the project was halted, marking a victory for the environmental movement.