United States. National Park Service

“ Entire logs were blasted to obtain the quartz and amethyst crystals often found within the logs, and much agate was carried away for making jewelry. The erection of a stamp mill near the forests to crush the petrified logs into abrasives offered the most serious threat. Alarmed, the citizens of Arizona, through their territorial legislature, petitioned Congress to make the area a national reserve 2 “so that future generations might enjoy its beauties, and study one of the most curious results of nature’s forces.” ”

“ As a result, the torrential summer rains that fall in northern Arizona rapidly cut the banded, bentonitic beds into sharp, conical hills, turreted ridges, and sharp, interbranching canyons and ravines. When dry, the bentonite is hard and strong, thus preserving these intricate badlands forms during the long periods between rains. Locally, a hard sandstone caprock may prevent rapid erosion of the shales beneath to form an abrupt-sided, table-topped butte or mesa. The resistant capping of the rim of the Painted Desert is composed of ancient volcanic rock. ”

“ In the monument are six separate “forests” where giant logs of agatized wood lie prostrate, surrounded by numerous broken sections and smaller chips and fragments.
The area is a part of the Painted Desert of northern Arizona, a region of banded rocks of many hues carved by wind and rain into a fantastic landscape. Here and there beds of shale contain perfectly preserved fossil leaves of plants of a remote age. Occasionally the bones of giant reptiles and amphibians are washed from their burial places in the deposits. ”