Fossil Hunting in Arizona

by Carla Jean McKinney
You can find fossils throughout Arizona.

You can find fossils throughout Arizona.

Hemera Technologies/ Images

With a history of massive geological changes throughout prehistoric times, Arizona offers rich opportunities for fossil hunting. In nearly all parts of the state, you can find many varieties of plant, invertebrate and vertebrate fossil specimens, from microscopic nanofossils to the bones of large dinosaurs. Combining hiking and history, amateur fossil hunting opens doors to the past and makes a significant contribution to ongoing scientific research and fossil study.

Fossil Hunting Opportunities

Opportunities to hunt and learn about fossils abound in Arizona. Individuals and groups can plan excursions to known fossil finds in the northern and southern parts of the state. Museums, such as the Arizona State Museum in Tucson, and research groups from the state's three universities offer volunteer opportunities for children and adults to assist at ongoing fossil excavation sites. The Arizona Sonora Desert Museum near Tucson, which displays a variety of fossils including large dinosaur skeletons found in the southern Whetstone Mountains, also hosts interactive learning experiences relating to fossils and the area's distant past.

Southern Arizona: Where Dinosaurs Walked

The southern half of the state, from roughly the Phoenix area south to the Mexican Border, experienced massive geologic changes in prehistory. These include violent volcanic activity and creation of inland seas, which covered the area in water and left behind numerous marine fossils. Rocks in the Saguaro National Monument in the Tucson Mountains reveal impressions of plants, the tracks of smaller reptiles and mammals, and even water drops from these ancient times. Farther south, in the Benson-Saint David area and Whetstone Mountains, searchers have found dinosaur bones, revealing a new species known as the Sonorasaurus, native only to this area. Along the banks of the San Pedro River, you can find numerous fossil bones, including those of larger mammals and reptiles.

Northern Arizona: The Petrified Forest

Northern Arizona, with its vast open areas largely owned by the Hopi and Navajo tribes, is home to the Petrified Forest, an area rich in fossilized wood. On the Black Mesa and in the canyons near Kayenta, shale outcrops contain numerous plant and small invertebrate fossils as well as some dinosaur teeth and bones. Near Shongopori and Oraibi on the Hopi Reservation, numerous fossil bearing outcrops reveal traces of the ancient inland seas that converged on the area in the late Cretaceous period.

Permissions and Permits

Although fossil hunting is open to anyone, experts advise checking for any applicable regulations pertaining to fossil hunting and fossil removal in specific areas. For hunts on private land, you will need permission from the owners. Public lands may require permits and have other legal restrictions. In national parks and monuments such as the Saguaro National Monument, rules permit hunting for fossils, but it is illegal to remove any fossils found. State lands managed by the Bureau of Land Management may require a permit for a fee, which allows the hunter to remove small amounts of plant and invertebrate fossils for personal collections. On Indian lands, you need to obtain permissions from the tribal governments, and in the large areas managed by the US Forest Service, collecting for personal use is free with permission.

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