Missouri’s rolling hills and ancient bedrock hide a quieter chapter of Earth’s story — old volcanic centers and igneous exposures that shaped local landscapes long before modern settlements. Visitors and curious locals often pass these rocky outcrops without realizing they’re walking across volcanic remnants.
There are 5 Volcanoes in Missouri, ranging from Arcadia Valley to Taum Sauk Mountain. For each, the entries below use the fields Type,Location (county; lat,long),Age (Ma), which you’ll find below.
Are any of these volcanoes still active?
No — Missouri’s volcanic activity dates to the deep geologic past, so the features you see are long-extinct volcanic centers and igneous intrusions rather than modern eruptions; expect old lava flows, hardened vents and eroded rock rather than steaming craters.
Where are good places to see volcanic features and what should I look for?
Start with protected areas around Taum Sauk Mountain and Arcadia Valley, where outcrops and rock ledges expose igneous textures; look for dark volcanic rock, columnar structures, and map or park signs, and consult state park guides or the Missouri Geological Survey for access and coordinates.
Volcanoes in Missouri
| Name | Type | Location (county; lat,long) | Age (Ma) |
|---|---|---|---|
| St. Francois Mountains | Proterozoic volcanic complex (rhyolite flows & centers) | Iron County; 37.55,-90.60 | 1,470 Ma |
| Taum Sauk Mountain | Rhyolite flow / volcanic center | Reynolds County; 37.57,-90.78 | 1,470 Ma |
| Johnson’s Shut-Ins | Rhyolite flow (shut-in channel) | Reynolds County; 37.57,-90.86 | 1,470 Ma |
| Pilot Knob | Volcanic knob / eruption center (rhyolite) | Iron County; 37.62,-90.66 | 1,470 Ma |
| Arcadia Valley | Cluster of volcanic centers / resistant rhyolite peaks | Iron County; 37.60,-90.64 | 1,470 Ma |
Images and Descriptions
St. Francois Mountains
The St. Francois Mountains are a Proterozoic volcanic complex in southeast Missouri, made of ancient rhyolite flows, dikes, and volcanic centers. Rugged exposures are nationally notable and many are visitable in state parks and forests, showing Missouri’s oldest volcanic rocks.
Taum Sauk Mountain
Taum Sauk Mountain is Missouri’s highest point, underlain by resistant Proterozoic rhyolite flows that formed part of an ancient volcanic center. Trails and a lookout in Taum Sauk State Park allow visitors to view and walk across these volcanic outcrops.
Johnson’s Shut-Ins
Johnson’s Shut-Ins showcases rivers channeled through tough Proterozoic rhyolite flows; the resulting smooth potholes and channelized rapids are classic volcanic-rock features. The state park has trails, overlooks, and safe visitor areas to see these ancient lava-derived rocks up close.
Pilot Knob
Pilot Knob is a prominent rhyolitic knob in Arcadia Valley, part of ancient volcanic centers that hosted iron mineralization and historic mining. The exposed volcanic rocks and nearby parks make it an accessible example of Missouri’s ancient volcanism and mining history.
Arcadia Valley
Arcadia Valley contains resistant Proterozoic volcanic peaks and dikes, including Iron Mountain and Pilot Knob. The eroded volcanic landscape is easily visited from roads and overlooks, and it illustrates Missouri’s ancient volcanism and its links to historic iron mining.
