[1] The John D. Dingell, Jr. Conservation, Management, and Recreation Act, signed March 12, 2019, expanded the Bisti/De-Na-Zin Wilderness by approximately 2,250 acres.

[7] The badlands expose the longest, most complete, and most richly fossiliferous sequence of beds spanning the Cretaceous-Paleogene boundary in any single sedimentary basin in the world.

)[8] The Fruitland Formation records flood plains and delta environments behind the receding shoreline, including swamps in which economical deposits of coal were formed.

[8] The sandstone of the Farmington Member reflects a time of uplift somewhere nearby, producing high ground from which coarse sediments were eroded.

[7] Some 200 species of plant or animal fossils have been identified in the combined Fruitland and Kirland Formations, most of which are found in the Bisti/De-Na-zin Wilderness.

The exact Cretaceous-Paleogene boundary, marked by a thin clay layer in other locations, is missing in a time gap between the two members of the formation.

[7] The Ojo Alamo Formation records a time when the Bisti/De-Na-Zin Wilderness was a seasonal tropical forest in which a wide variety of species grew, but in which angiosperms (flowering plants) were dominant.

[12] The beds contain fossils of the earliest animals of the Paleocene, and define the Puercan and Torrejonian North American Land Mammal Stages on the geologic time scale.

[12] The area became part of the western side of the San Juan Basin which formed during the Laramide orogeny and tilted the beds to their present 5-degree angle to the northeast.

[7] A small variety of wildlife can be found in the Bisti/De-Na-Zin Wilderness, including cottontail rabbit, coyote, badger, porcupine, and prairie dog.

Bird species include pinyon jay, raven, quail, dove, ferruginous hawk, prairie falcon, and golden eagle.

[1] Recreational activities in the Bisti/De-Na-Zin Wilderness include hiking, camping, wildlife viewing, photography, and horseback riding.