The government should buy more than $1 billion worth of scenic and recreational land to help stave off development threats fueled by a decade of congressional neglect, environmental leaders said Saturday.

"If we put off these investments, either we'll lose the lands or end up paying a steeper price," said Wilderness Society president George T. Frampton Jr. "Once forests, fields and streams give way to fast-food strips and office buildings, they're gone forever."The Wilderness Society and a coalition of 19 other groups targeted more than 1 million acres it says are vital to wildlife, history and outdoor recreation.

The lands, primarily fragile areas bordering existing parks, forests and refuges, cover a total area larger than Rhode Island. They were targeted because of the threat of industry, farming and home-building. In most cases, the coalition said, there are willing sellers.

The most expensive purchase would be $35 million to add 1,100 acres to California's Santa Monica Mountains National Recreation Area, where the group says development threatens trails and coastal access in the Topanga and Tuna Canyons.

The largest buy would be $5 million for 60,000 acres in southeast Oregon at the Warner-Steens project area covering natural lakes, wetlands, desert mountains, aspen forests and at least six species of endangered fish.

Costs of the individual parcels range from $31 per acre to expand Oregon's Malheur National Wildlife Refuge by 32,000 acres, to $750,000 an acre to add 2 acres to the Weir Farm National Historic Site in Connecticut.

Congress has the authority to appropriate as much as $900 million annually from the Land and Water Conservation Fund for land purchases. Frampton said it has averaged only $230 million the last 10 years.

Oil companies pay into the fund to compensate the federal government for off-shore oil leases. The fund also gets money from the motorboat fuel tax and the sale of unneeded federal property.