GIVEN THE VOTE BY which the Senate Public Works Committee reported out an Alaskan lands bill the other day (17 to 1), it might seem as though the long battle were about to end.Well, it isn't. The conservation groups that have been struggling for years to preserve untouched as much as possible of Alaska's vast space regard many provisions in the committee's bill as disastrous. They are determined to mount the kind of lobbying effort in the Senate that persuaded the House last spring to pass a bill that tilts far more sharply toward preservation than the bill now moving toward the Senate floor.

The people who want to encourage mining, oil exploration and timbering in the Alaskan wilderness won most of the rounds fought in the Senate committee. The committee bill would provide federal protection for 95 million acres -- an area about the size of Virginia, West Virginia and North and South Carolina combined. But that is a reduction of 25 percent from the area placed in federal preserves by the House bill. In addition, the level of federal protection the Senate bill would give to many of those acres is considerably less than that provided by the House.

While the committee bill is awaiting action in the Senate -- and it may wait a long time, since there is a threat of filibuster -- careful attention should be paid to what is being proposed for at least four parts of Alaska. These are: Admiralty Island, where the local population wants to preserve a great forest and the timber industry wants to cut part of it; the Arctic Wildlife Range, where oil and gas may lie under the breeding grounds of Alaska's largest herd of caribou; Misty Fjords, where a borax mine is competing with magnificent wilderness; and Gates of the Arctic, where the fight is over permitting roads and towns and mining in an area designated by the House as a national park.

The standard that ought to guide the Senate in resolving these conflicts, and the many others that undoubtedly will be brought before it, is simple. The areas of Alaska protected now will always be available for development in the future; those that are developed now cannot be protected in the future. Putting land into parks, wilderness area and other heavily protected categories is not, as the developmental interests sometimes claim, locking up the land forever. It is letting future generations decide what to do when and as they wish. The Senate should seize the chance to join the House in giving those future generations a great gift.