BACK IN SEPTEMBER, Interior Secretary

James Watt followed through on a pledge he made last spring to "open wilderness areas," thereby precipitating the latest in a series of confrontations with Congress. For the first time ever, the Department of the Interior issued leases for oil and gas drilling in a designated wilderness area, specifically the Capitan Mountain Wilderness of New Mexico.

The 1964 Wilderness Act allows leasing to take place in wilderness areas until 1984, but no previous secretary of the interior has seen a need to do so until likely non-wilderness areas were explored and developed. The New Mexico leases were the first actually to be issued, but a number of environmental assessments--a prerequisite to issuing a lease--are also under way for drilling in wilderness areas of Wyoming, Arkansas and near the Big Sur coast of California.

In the now-familiar style that seems to ask for a fight, Mr. Watt issued the leases without the legally required environmental impact study, without public notice and opportunity for public comment and without first informing Congress. The action has provoked a rebellion--even among Republicans on the House Interior Committee. Today the committee is expected to consider ways and means to block Mr. Watt's action, possibly including a measure that would declare a state of emergency throughout the entire wilderness system.

The most important question for the committee to explore is why Mr. Watt feels compelled to see oil and gas drilling in the wilderness. At a hastily called news conference yesterday, he claimed that the law requires him to do so. It does not. It permits mineral leasing in the wilderness but neither directs nor encourages it.

Nor is there an urgent need to develop these oil and gas reserves. Wilderness areas--those that retain "primeval character and influence . . . with the imprint of man's work substantially unnoticeable" -- make up less than 2 percent of the continental United States. A just-completed study released by former congressman Joseph Fisher, now with the Wilderness Society, finds that designated and potential wilderness areas together contain just 2 percent of U.S. oil reserves and 1.6 percent of gas reserves. Even if these figures are off by as much as 100 percent, nearly all potentially recoverable oil and gas reserves would still lie outside wilderness areas, most of them on non- federal lands.

Once disturbed, wilderness is difficult if not impossible to restore. The oil and gas beneath it is not going anywhere. Unless Mr. Watt can explain why this small amount needs to be developed now, it should be left undisturbed until it's really needed.