From 1953 to 1958, the Tutts leased a parcel known as King Tutt No. 1 to a succession of operators, the largest of which was Vanadium Corp. of America.
In 1989, Navajo inspectors visited the abandoned site and found huge mounds of dust and ore rich in uranium and other heavy metals — vanadium, selenium and arsenic. They also found products of uranium's decay — radium, radon gas, thorium and lead.
About 200 mines had been bored into the mesa. Hoskie suggested lumping them into one Superfund application. She believed that "the sheer number of sites" would make the application hard to reject.