The biggest land conservation bill of the century - a controversial measure that would double the size of the National Park system by setting aside about a third of Alaska for parks, preserves, refuges and wilderness - faces a close vote in the House Rules Committee next week.

After holding a hearing this week, the Rules Committee delayed until Tuesday a vote on whether to send the bill to the House floor. The delay is believed to help opponents of the bill by giving the mining and timber interests, building trades and carpenters unions more time to lobby the 16 members of the Rules Committee.

If it can clear the Rules Committee, it's expected that the House will pass the bill, since it is endorsed by the House leadership and is the "number one conservation priorty" of President Carter. The House is scheduled to take up the bill Wednesday.

House passage, however, would not mean the massive bill would be home free. Although Sen. Henry M. (Scoop) Jackson (D-Wash.) has agreed to begin work on the bill in June in his Energy and Natural Resources Committee, the opposition of Alaska's two senators, Ted Stevens (R) and Mike Gravel (D), and their threatened filibuster, make it questionable whether the bill would clear the Senate. The Senate traditionally does not pass legislation affecting a state that the state's senators oppose.

In fact, that argument is one of the strongest influences on the Rules Committee. Rep. Lloyd Meeds (D-Wash). a member of both the Rules Committee and the Interior Committee, whose version of the Alaska lands bill he opposes, argues there is no point in having the House members take a stand on a bill that has "absolutely no chance" to pass the Senate. "The best thing that can happen is if we hold it here, sit down and negotiate and get something that will pass both places," Meeds says.

Interior Committee Chairman Morris Udall (D-Ariz.) disagrees. Alaska lands belong to the nation, just as the Grand Canyon in his state does, Udall says, arguing that two senators should not be able to block the preservation of what he calls the "crown jewels" of the nation's treasury of wildlife. Udall also feels passing the bill would pressure the Senate into acting.

In addition, protection against development of the lands under question ends on Dec. 18 and Udall feels its imperative to act before then.

The bill sets aside 100 million acres - equal to the size of the state of California, or the territory between Washington, D.C. and Maine - as parks, preserves, refuges and wilderness.

In a single stroke, the size of the National Park system would be doubled. Udall and Rep. John Seiberling (D-Ohio) argue that the bill presents a unique opportunity to preserve the last of the country's great wilderness areas. They also argue that the fragile ecosystem demands preservation if the wildlife such as musk oxen, polar bears, grizzly, caribou, and hundreds of species of birds is to be maintained.

On the other hand, many state officials, and mining and timber interests argue that the bill is a measure that unfairly limits growth and development and limits mining for needed gold, copper, tin, uranium and silver in addition to oil and gas.

Rep. Don Young (R-Alaska) said he wants the state to be guaranteed access across the lands, wants the state to be able to pick 5 million acres of 16.2 million acres it has coming to it in a grant of land made to the state upon statehood in 1959, and wants a decreased wilderness area. He supports a Meeds substitute that would contain only 33 million acres of wilderness as opposed to 65.54 million in the bill.

Udall argues that the bill has already been "drastically compromised," with the wilderness areas cut by more than half from an original 142 million acres. Udall also argues that 70 percent of lands with metallic mineral potential will be outside the system and 80 percent of the lands will be open to development and all potential oil and gas lands will be open to development.

One dispute centers around timbered land in the southeast where Meeds, joined by the carpenters and builiding trades unions, feel timber cutting would be restricted and jobs lost.

Udall argues the bill allows for substantial growth in timber cutting.

One further complication is that the bill was also referred to the Merchant Marine Committee, and the two committees put out a "consensus bill," the most controversial part of which is dropping of a portion of the Interior bill that would have set up a mechanism for "unlocking" mineral exploration on some 67 million acres that would otherwise be restricted.

Meeds complained that neither committee has approved the "consensus" bill and that committee mambers might object to dropping that provision.

But the final determination as to whether the bill clears the Rules Committee may rest with the leadership and how hard it wants to push for it, since the Rules Committee is considered an "arm" of the leadership.