In 1980, the U.S. Fish and Wildlife Service (USFWS) designated about as essential habitat where the groundwater most influenced the water level in the Hole. One of the identified goals of the recovery plan was to maintain the aquifer at such levels that the population fluctuates from 300 in winter to 700–900 in late summer. The water source for Devils Hole pupfish were now protected from industrial use, but the rest of Ash Meadows was unprotected. When the USFWS declined to purchase the land from Cappaert Enterprises, Ash Meadows was sold in 1980 to a property development company, Preferred Equities Corporation, who acquired additional nearby land with the intention of creating 33,636 residential parcels altogether. As the original injunction limited water with exception to domestic purposes, it was unclear if residents of the proposed subdivision would have to limit water usage in respect to the water level of Devils Hole. In 1982, Secretary of the Interior James Watt approved the emergency listing of two more Ash Meadows fish, the Ash Meadows pupfish ("Cyprinodon nevadensis mionectes") and the Ash Meadows speckled dace ("Rhinichthys osculus nevadensis"). Further development by Preferred Equities would therefore almost certainly violate the Endangered Species Act. After protracted negotiations, The Nature Conservancy (a nonprofit) was able to purchase Ash Meadows for $5.5 million in February 1984, with reimbursement from the U.S. Federal Government of $5 million. By June 1984, Ash Meadows National Wildlife Refuge was established, as The Nature Conservancy transferred the property to the government. By 1986, a recovery plan was drafted for all of Ash Meadows, encompassing Devils Hole.