Uranium deposits in the Poison Canyon Trend, Ambrosia Lake Subdistrict, Grants Uranium District, McKinley and Cibola counties, New Mexico
— Virginia T. McLemore

The Poison Canyon uranium discovery was an important economic event in the Grants Uranium District, New Mexico. Not only was it the first sandstone-hosted uranium deposit discovered and mined that ultimately led to the larger Ambrosia Lake Trend, but the main types of uranium deposits, primary and redistributed, were first recognized in the Poison Canyon Trend. More than 10 million lbs of U₃O₈ were produced from mines in the Poison Canyon Trend and additional historic resources remain. The Poison Canyon Trend is south of the Ambrosia Lake Trend, north of Grants and Milan in the southern San Juan Basin. The uranium deposits are hosted by the Poison Canyon sandstone, an informal name (economic usage) of one of the uranium-bearing sandstone units at the top of the Westwater Canyon Member or the lower part of the overlying Brushy Basin Member of the Jurassic Morrison Formation. Many of the uranium deposits in the Poison Canyon Trend have been mined out and what uranium remained at these older mines is probably uneconomic to recover, especially in the western portion of the area. The mineral-resource potential for uranium in the unmined portions of the Poison Canyon Trend is high, especially in the eastern portion of the trend. However, it is unlikely that any of these deposits will be mined in the near future because of economic conditions and numerous challenges to mine uranium in New Mexico.