Natural Arches, Bridges & Tunnels
Missouri has around 100+ natural arches, bridges, and tunnels located around the state, a majority being located within the Ozark region. Here is a link to a map I have created highlighting many of these features, most are listed within Dr. Thomas Beveridge's Geologic Wonders and Curiosities of Missouri. Map Here
How do Natural Arches, Bridges and Tunnels form?
Arches, bridges, and tunnels have two distinct features; they feature two entrances/exits and rock that reaches overhead that connects in the middle. The most common way they form is from collapsed cave systems. When a cavern collapses, it is possible for only half of the rock to fall, leaving an archway or tunnel behind. The collapse could occur from either too much rock eroding away in the cavern, leading to collapse, or from water dripping in overhead causing a hole to form in the roof of the cavern, eventually wearing away over time and leading to a large opening. Some natural tunnels form from water flowing through soluble rock. Over many many years of constant flowing water, rock walls begin to give way, which can lead to a tunnel forming. Bennett Spring Natural Tunnel is a good example of this.
Arches, bridges, and tunnels have two distinct features; they feature two entrances/exits and rock that reaches overhead that connects in the middle. The most common way they form is from collapsed cave systems. When a cavern collapses, it is possible for only half of the rock to fall, leaving an archway or tunnel behind. The collapse could occur from either too much rock eroding away in the cavern, leading to collapse, or from water dripping in overhead causing a hole to form in the roof of the cavern, eventually wearing away over time and leading to a large opening. Some natural tunnels form from water flowing through soluble rock. Over many many years of constant flowing water, rock walls begin to give way, which can lead to a tunnel forming. Bennett Spring Natural Tunnel is a good example of this.
Rockpile Mountain Wilderness Natural Arches
The Pinnacles Natural Arches
Rockpile Mountain Wilderness Natural Arch
Mill Street Natural Arch and Cave Spring
Rockpile Mountain Wilderness Natural Arch
Dry Sac Natural Arch
Rockbridge Memorial State Park Natural Bridge
Bennett Spring Natural Tunnel
Ha Ha Tonka Natural Bridge
Cassville Natural Bridge
Pickle Springs Natural Arches