WASHINGTON (CNN) -- President Clinton plans to unveil a $1 billion environmental plan Tuesday, nearly half of which would be used to buy vulnerable land in and near national parks, Civil War battlefields and other areas.

Vice President Al Gore unveiled the first part of the environmental package Monday, announcing a plan that proposes to use $700 million in tax credits to finance a $10 billion bond program aimed at creating suburban parks, greenways and other open space.

That proposal is aimed at dealing with suburban sprawl, while the new initiative is directed at restoring and protecting undeveloped, but vulnerable, forests, grasslands, beaches and marine sanctuaries, officials said.

Gore is to be on hand Tuesday when Clinton announces his initiative during a speech at the National Arboretum in Washington.

The proposal calls for buying land in the Everglades, the Mojave Desert, the Northern Forest in Maine and land along the Lewis and Clark Trail and several Civil War Battlefield sites.

Saving America's 'natural treasures'

The administration calls the increased funding, which will be included as part of the administration's fiscal 2000 budget proposal to Congress, "one of the highest increases for the environment in history."

"The goal is to substantially expand federal efforts to save America's natural treasures and provide significant new resources to states and communities, to protect and restore farmland, city parks and open spaces," White House spokesman Barry Toiv said.

The proposal includes $442 million for direct land purchases. Included among the parcels are:

• $84 million toward land acquisition in the Everglades;

• $53 million for parcels in the Northern Forest in Maine;

• About $50 million for the Cetellus land reserves in the Mojave Desert.

• Various land parcels along the Lewis and Clark Trail from Missouri to the Northwest.

• $68 million over three years for Civil War battlefields, including Gettysburg and Antietam.

The money would come from a land and water conservation fund financed largely by federal royalties from offshore oil drilling. Nearly 30 years ago, Congress authorized spending up to $900 million per year for land purchases from the fund.

The president will also ask Congress to declare some 5 million acres of back country in 17 national parks and monuments under permanent wilderness protection, Toiv said. Included on that list are properties in Yellowstone, Teton and Glacier National Parks.

Reuters contributed to this report.