The House last week approved a bill expanding Virginia's protected wilderness area by 50 percent after a major paper plant dropped its longstanding objection to the proposal.

Reps. James R. Olin and Rick Boucher (D-Va.), chief sponsors of the bill, hailed the House action Tuesday as a major step toward completion of a wilderness system that straddles Virginia and West Virginia.

"Those who live in Virginia and those who come to Virginia to visit are going to be able to see and experience the national forest in its natural state free from the works of man," Olin said.

Boucher said he expects the Senate to approve the measure swiftly.

The bill would add about 25,000 acres to Virginia's wilderness area. Included are four sites in Southwest Virginia managed by the U.S. Forest Service that have been under consideration for wilderness designation for three years: Rough Mountain (9,300 acres), Rich Hole (5,600 acres), Barbour's Creek (5,800 acres) and Shawver's Run (4,467 acres).

The measure would add 2,500 acres in West Virginia to the adjoining Mountain Lake Wilderness Area.

Congress voted in 1984 to set aside 56,000 acres in Southwestern Virginia as protected wilderness, in response to more than a decade of lobbying by conservationists. Proponents favored adding 25,000 acres to the program but encountered stiff opposition from the Westvaco Corp., a major paper plant in the area.

Westvaco, which employs 2,000 workers in Covington, Va., feared that the wilderness designation of nearby Barbour's Creek would bring with it more stringent air quality standards that would hamper its mill operations. As a compromise, Congress set aside the additional 25,000 acres as "wilderness study areas."

In June, the company dropped its opposition after concluding that the proposed wilderness areas would not be reclassified Class I under the Clean Air Act, a change that would have reduced allowable plant emissions severely.

Jack A. Hammond, Westvaco vice president and manager of the Covington Mill, said his firm had received assurances from Virginia's congressional delegation that the proposed wilderness areas, currently designated Class II, would not be reclassified Class I.

"I still believe that it is possible to protect jobs and to protect wilderness simultaneously," Olin said last week.

The four areas to be added to the wilderness program are in the George Washington National Forest and the Jefferson National Forest.

Rough Mountain has rugged terrain with steep slopes. Rich Hole has large stands of timber with some trees up to six feet in diameter and more than 200 years old. Barbour's Creek and its tributary, Lipes Branch, are popular fishing streams. Shawver's Run is a recreation area with trout streams.