Agate Bridge [Suggest Edits]

Description

Agate Bridge is likely the most famous of the individual petrified tree specimens found at Petrified Forest National Park. Spanning 110 feet, this great log was once a towering tree. As the tree died, it was carried downstream to a floodplain, where it was quickly buried in sediment. By limiting the amount of oxygen that the log was exposed to, the tree began the petrification process. As silica began to replace the tree, it eventually became the log that is visible today.

A remarkable twist in the tree's history brought it into the position of spanning a void. The tree did not always sit as it is perched now, rather the sediments that this erosion resistant form used to rest on were slowly eroded away through natural forces. Being made up of silica instead of organic material, the tree was able to avoid most of this erosion.

The more modern history of Agate Bridge shows the evolving views of the National Park System. In 1911, visitors and conservationists were afraid that the bridge would collapse, and reinforced the former tree with support. Masonry pillars were the chosen medium, which supported the tree for 6 years until the concrete slab that exists today was installed.

Even with enhanced stability, Agate Bridge is an incredible sight, especially when the complex and lengthy (~200 million years) history of the formation is considered. Visitors will wonder at this spectacular sight, and Agate Bridge is a necessary stop when visiting Petrified Forest National Park.

On the Road: A short distance from the parking area to the overlook is all that is required to see this wonder.

Gem Type: Rock Formation