WASHINGTON - The House passed legislation Friday that included a permanent ban on gas, oil and mineral exploration along Montana's Rocky Mountain Front.

Sen. Max Baucus, D-Mont., added the language to a tax bill that the Senate is now hoping to pass before adjourning for the year. The drilling provision would make permanent a 1997 moratorium on drilling on the front and make it easier to retire existing leases.

Drilling on the Rocky Mountain Front has been the subject of passionate debate for years. Running for about 100 miles in a part of west-central Montana where the mountains rise dramatically from the plains, the Front is home to an array of wildlife and known for its solitude.

Montana's congressional delegation is split on the ban.

Republican Rep. Denny Rehberg, Montana's only member of the House, opposes it and called it "foolhardy" when the larger tax bill was introduced Thursday. He says drilling is needed at a time when the United States is struggling to meet its energy needs.

But Rehberg voted for the larger bill, which also includes $38 billion in tax breaks for businesses, higher education costs and schoolteachers as well as credits for alternative energy initiatives.

The legislation now moves to the Senate, which is expected to consider the bill late Friday evening or over the weekend. The legislation will face some opposition in that chamber, where some conservatives have complained about its cost.

Republican Sen. Conrad Burns added a similar provision to an Interior Department spending bill that the new Democratic Congress will consider next year. But that legislation could face obstacles as well, as Burns lost his November re-election bid to Democrat Jon Tester and will no longer be the bill's sponsor.

The drilling ban would give oil and gas companies a tax break if they sell their leases to nonprofit groups. That break would be equal to 25 percent of the capital received by the seller.

According to Baucus's office, that would apply to 60 current leases on the front.

Two energy firms agreed earlier this year to sell and donate the mineral leases they hold along the front. Supporters of the ban have said a permanent solution enacted by Congress would help finalize those deals.