• Natural Bridge Trail


    National Monument Arizona

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  • Visitor Center Summer Hours in Effect Beginning May 1, 2014

    Summer hours are in effect for the visitor center from May 1 - October 12, 2014 from 8:30 am - 4:30 pm. The hikers' shuttle will leave the visitor center at 9 am. For more information call 520-824-3560 0. More »

  • Entrance and Camping Fees Waived this Summer

    From June 1 through September 30, all entrance fees will be waived and federal lands passes will not be available for purchase at the park. More »

  • Mushroom Rock Trail Closed to Horses, Hikers Use Caution

    Mushroom Rock Trail is closed to horses due to hazardous conditions caused by recent flooding. Hikers use caution. Trail is washed out in place and may be difficult to follow.


This rock is dotted with several kinds of lichens, which attach closely onto the surface, and may even become encrusted onto the surface.
Lichens on rock D. Dougall

Lichens are small plants that are made up of two components – a fungus and algae. The fungus provides the structural components of the plant, while the alga provides nutrition and energy via photosynthesis. Lichens lack true roots, stems and leaves, although some forms grow to resemble these common plant parts. Lichens reproduce using spores or detachable fragments.

Lichens grow on surfaces such as rock, tree bark, or other substrates, and obtain most of their nutrients from the atmosphere. Because lichens gather materials that are washed from the air by precipitation, they can be used to monitor certain pollutants that travel through the air, such as heavy metals and sulfur. There are many species of lichens, and upon close inspection you can see the differences in color and shape. When viewed from a distance however, they often create a more uniform coloration of yellow, green or brown, that "paints" the surface of the rocks and cliffs.

Did You Know?

Geronimo and Naiche

Southeast Arizona was home to the Chiricahua Apache, under the leadership of Cochise. They surrendered for the final time in 1886 and were sent first to Florida and later to Fort Sill, Oklahoma. Many found homes in the hills of today's Chirichaua National Monument.