The Federal Land Policy and Management Act of 1976 calls on the Bureau of Land Management to inventory and study its roadless areas for wildnerness characteristics. Criteria include a size of usually at least 5,000 acres, opportunities for solitude, and other ecological, geological, educational, historic, scientific and scenic values.
After an inventory process that included significant public input, BLM's Conservation System now manages 604 Wilderness Study Areas with almost 14.1 million acres. Congress has since designated some as wilderness. Until Congress reviews all of the Wilderness Study Areas, the Conservation System manages them to preserve their suitability for wilderness designation.