Desert Protection Initiative Renewed. CALIFORNIA

MOST of the epic environmental battles in California, one of the nation's most environmentally minded states, have revolved around the redwoods, the Pacific Coast, and the Sierra Nevada mountains. Now, however, the focus is shifting inland - to the vast California desert, an austere but varied land of giant sand dunes, sawtoothed mountains, twisted trees, and Tobasco temperatures.

Conservationists are reviving their push to see large areas of the California desert protected as wilderness area or national park land. But miners, ranchers, off-road-vehicle enthusiasts, and others want to keep it from being, as they see it, sealed in a Mason jar of federal protection and put on a shelf so no one can use it.

The move to protect the California desert will be one of the most ambitious - and contentious - attempts to expand the national park system in the 101st Congress.

Last session, lawmakers added more units to the system than at any time since 1980. This included one new national park, in the American Samoa, as well as 13 new recreation areas, monuments, historic sites, and other entities in 11 states. At least a half dozen parks expanded boundaries and many others came under additional protections.

``There was a real flurry of activity in the last two weeks of the session,'' says Bill Lienesch of the National Parks and Conservation Association.

This time around, however, environmentalists are expecting less benevolence. Politically, the climate would seem right for expansion. Conservationists say George Bush may be more amenable to their interests than Ronald Reagan was.

Yet it is still too early to tell how much support the new administration will give national parks. ``I think a lot of proposals are at the gestation stage,'' says Steven Whitney, a lobbyist with the Wilderness Society.

Among the new units likely to be pushed again this year will be the Tall Grass Prairie National Preserve in Oklahoma. It has been stymied by disputes over size and over grazing and mineral rights.

Other ideas that may get aired this session include the creation of a national monument to protect ancient rock carvings (petroglyphs) in New Mexico, expansion of the Florida Everglades, and the establishment of a river-basin national park in a yet to be determined location.

Yet some of the most vociferous debate is likely to emerge over protection of the arid land here. Environmental groups consider the California desert one of the last great unprotected wilderness areas in the United States.

Although efforts to protect it have not gotten far in Congress in the past, proponents are now renewing their push. Sen. Alan Cranston (D) of California recently introduced a desert pro-tection bill in the Senate. A companion measure is being backed by California Democrat Mel Levine and 41 co-sponsors in the House.

The measures seek to preserve 7.5 million acres of southern California land, 4.5 million of which would be in wilderness areas and the rest in three national parks. Two parks would be created by upgrading to national park status Death Valley and Joshua Tree national monuments. A third area, the Mojave Desert, would be created as a park on the state's eastern edge.

``This is one of the priceless resources California offers to future generations,'' says Mr. Levine.

Proponents contend the ``fragile and unique'' environment - which contains 700-foot sand dunes, dozens of mountain ranges, 750 species of wildlife, and the world's largest Joshua tree forest - is being threatened by encroaching urbanization from the Los Angeles basin.

Opponents counter the legislation would cut off vast stretches from recreationists, tie up mineral deposits, and undermine the livelihood of ranchers.

``The East Mojave is not going to become downtown Los Angeles,'' says Marie Brashear of the California Desert Coalition, a group made up of mining, grazing, off-road vehicle, and other interests.

To win over critics, sponsors have slightly altered their original proposals. For instance, the military, which has several bases in the area, has been assured it will be able to continue flights over the desert.

But the measures still face a tough fight in Congress. One key in the Senate: whether California's junior senator, Pete Wilson, will jump on board. The Republican didn't support the legislation last year and has yet to indicate what he will do this time around.