Big Laurel Branch Wilderness took a step toward a nearly 4,500-acre growth spurt Tuesday when the Senate Agriculture Committee passed legislation by Tennessee’s senators.

The Tennessee Wilderness Act would add 4,446 acres to the wilderness, now mostly located in Carter County.

“To say that this land is among the wildest, most pristine and beautiful areas in East Tennessee sets a very high bar, since the region includes the Appalachian Mountains and our nation’s most visited national park, the Great Smoky Mountains National Park,” Sen. Lamar Alexander said in prepared remarks to the committee.

Alexander and Sen. Bob Corker first introduced the bill in 2010.

The addition is the second-largest portion of the nearly 20,000 acres of Cherokee National Forest the act would place under what is the most restrictive federal land use designation. The act would also create a 9,038-acre wilderness in Monroe County and add nearly 3,000 acres to the Sampson Mountain Wilderness in Unicoi and Washington counties, as well as making three other, far smaller, additions to other areas.

The measure passed by voice vote.

The existing Big Laurel Branch Wilderness runs from the Horseshoe area northeast along the slopes of Iron Mountain and along about six miles of the Appalachian Trail, and runs along Watauga Lake for more than three miles.

According to the website for Tennessee Wild, tnwild.org, the proposed addition would follow northeast along the Appalachian Trail on the slopes of Iron Mountain for more than 4.5 miles, to just south of Shady Valley.

Alexander noted the addition would have no impact on privately owned land or increase costs for taxpayers.

“Wilderness designation is the highest form of protection we can give to public lands and ensures that they will be preserved for future generations,” the senator said. “No roads, vehicles or permanent structures are allowed in designated wilderness areas.”

The parcels were originally recommended for wilderness designation by the U.S. Forest Service as part of its 2004 forest plan, which included extensive opportunities for public comment.

“As the result of extensive local public input, this legislation has broad support from fishermen, hunters, backpackers, hikers, artists, pastors, botanists and state and local officials — all of whom support the bill,” Alexander told the committee.

The Big Laurel Branch wilderness currently encompasses about 6,330 acres.