A rocket test facility built by Hercules Inc. in 1976, on the Goshute Indian Reservation, in remote Skull Valley, in northern Utah. Later operated by AlliantTech Systems (ATK), which bought Hercules, along with its primary rocket facility near Magna, Utah, in the early 1990's. Activity at Tekoi has decreased since the 1980's, with some of the testing moved to the Thiokol plant near Promontory. Russian signage on the perimeter of the facility is due to the fact that this site was designated as "inspectable" for Russian inspectors as part of the START Treaty (as were other sites in Utah that were used for the development and storage of submarine launched ballistic missiles, at Oasis, Hill AFB, and ATK at Magna).