Mississippi Petrified Forest

Around 36 million years ago, during the Oligocene, this portion of Mississippi was a flood plain, with a large river running through stands of ancient Sequoia, Oak, Fir, Maple, and some other species of trees that are now extinct. At some point, the river flooded in a flash storm, and many of the trees were knocked down, tumbled downstream, and became packed together into a large logjam. This was then quickly buried by sand and clay. Over the next few million years, the wood in the buried logs was gradually replaced by minerals from the groundwater, turning them into stone. The overlying sediments were then slowly worn away by erosion, exposing the petrified wood at the surface.

The petrified logs were known at least as far back as 1854 (and both Union and Confederate soldiers camped here at separate times during the Civil War). In 1888, Frank H Knowlton of the US Geological Survey authored some papers describing several new species of fossilized trees. For almost 100 years the area was unprotected and was believed to have been abandoned, and freelance rock hunters came in and removed hundreds of tons of petrified wood.

In 1962 the land was purchased by the local Shabilion family, which still owns it. They put up a fence to protect the logs, and opened it to the public as a park a year later. In 1966 it was registered as a US National Natural Landmark.

Some photos from a visit.

The Visitors Center

Today, the area consists mostly of Loblolly Pine forest

It looks like wood—but it’s stone

This log has been cut off at the end to show the growth rings and the internal mineralization. No wood remains.

This log was a standing dead tree at the time of the flood—it had already rotted its interior out, leaving only the outer wood to be fossilized

This single log was broken into sections by ground movement after it was fossilized

Look at it, and you can see why this 7-ton weathered section of trunk is known as “The Frog”

These segments were once part of the same log. The height of the hill gives an idea of how deeply the fossilized logs were once buried in the soil.

This log has only just begun to weather out of the ground. There’s no way to know how much of it remains under the surface.

This large hollow piece was once the base of a standing dead tree

The thick clay layer here containing the logs is part of the Forest Hills Formation

A large log eroding out alongside the pathway

A specimen of Floraoxylon, an extinct tree

The museum displays fossils and petrified wood samples from around the world

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