After Hurricane Irene damaged the Thoreau Falls Bridge in 2011, the U.S. Forest Service imposed a limit on hikers crossing the 60-foot span. Oct. 3, 2015. DAVID BROOKS / Monitor file

State Sen. Jeb Bradley wades across the East Branch of the Pemigewasset River upstream from the Thoreau Falls Bridge. Bradley, a proponent of replacing the bridge, argues that removing the bridge would cause too many hikers to make the dangerous river crossing. Oct. 3, 2015. DAVID BROOKS / Monitor staff

A hiker waits to cross the Thoreau Fall Bridge, which can hold only one person at a time. Oct. 3, 2015. DAVID BROOKS

The underside of the Thoreau Falls Bridge shows some of the damage that the two 60-foot logs have incurred. Some cracks cut halfway through the 2-foot-diameter logs. Oct. 3, 2015. DAVID BROOKS / Monitor file

J. Dan Abbe and Jon Morrissey of the U.S. Forest Service discuss the status and future of the Thoreau Falls Bridge during a tour of the site in October 2015. DAVID BROOKS / Monitor file

A map shows the location of the Thoreau Falls Bridge across the Pemigewasset River in the Pemigewasset Wilderness.

The Thoreau Falls Bridge, shown in October 2015, spans the Pemigewasset River in the Pemigewasset Wilderness. The bridge has fallen into disrepair, and debate over whether to replace or remove it has divided activists. DAVID BROOKS photos / Monitor file

The public has one more chance to give its opinion on the future of the last footbridge in the Pemigewasset Wilderness, a dilapidated log crossing of the East Branch of the Pemigewasset River that has come to symbolize the conflicting desires of maintaining true wilderness while allowing people to use it.

The White Mountain National Forest is seeking comments on what is called a draft environmental statement for the Thoreau Falls Trail Bridge Removal Project, which will decide whether to replace the bridge or remove it altogether. The statement does not lean to either approach, although it rejects a few options such as replacing the bridge with stepping stones or a cable car.

The statement does not discuss the potential cost of building a replacement bridge, and officials say damage to the bridge, including cracks halfway through one of the logs, cannot be repaired.

If no major objections arise, then the bridge, which has been limited to use by one person at a time since it was damaged during 2011’s Hurricane Irene, could be torn down as early as next summer, said Dan Abbe, who oversees the project for the national forest.

Although Thoreau Falls Bridge is relatively remote, lying an hour’s hike from the nearest road, its fate has created so much debate that last year the Forest Service scrapped its initial plan to make a decision with limited public input, instead taking a route that involves this draft environmental statement.

Proponents of replacing the bridge say it is a vital connection between the north and south portions of the 45,000-acre Pemigewasset Wilderness, and losing it would make it much harder and more dangerous for hikers. In particular, the possibility of losing the bridge drew outcry from wintertime hikers and cross country skiers, as the river rarely ices over completely and is virtually impossible to cross in winter.

In the summer, the bridge provides a connection between the Appalachian Mountain Club’s Zealand Falls hut to the north and Lincoln Woods Visitors Center on the Kancamagus Highway to the south, crossing a stretch of river that can be dangerous to ford after heavy rains.

Proponents of replacing the bridge – most notably state Sen. Jeb Bradley of Wolfeboro, the Legislature’s most prominent hiker – call it a vital connection to the heart of the Pemigewasset Wilderness. He has repeatedly expressed concern that removing it would be dangerous, saying he fears people would risk fording the river after investing so much time to get that far.

Opponents of replacing the bridge argue, however, that the lack of man-made structures is key to the wilderness experience. The Pemigewasset Wilderness Area in the heart of the White Mountains is unusual in that it is relatively accessible to millions of people in urban areas.

The bridge consists of a pair of 60-foot logs that were hauled in by horses and placed on concrete abutments when it was built in 1962.

The current bridge is likely made of Douglas firs brought from the West Coast, because no trees in this once-logged area were that tall in the ’60s.

The Pemigewasset Wilderness Area, in which the bridge lies, was created in 1984 when roughly 45,000 acres of the White Mountain National Forest were placed under the federal Wilderness Act, designed “to secure for the American people of present and future generations the benefits of an enduring resource of wilderness ... where the earth and its community of life are untrammeled by man.” The Wilderness Act puts sharp constraints on construction.

The bridge cannot be replaced with new trees under restrictions posed by the federal Wilderness Act, so a new bridge would have to be built from spans made of manufactured lumber brought in by helicopter. Removing the bridge would also require a helicopter to carry debris from the wilderness, according to the draft report.

Because the Thoreau Falls Bridge existed before the Wilderness Act, some proponents of replacement have argued that it is exempt. They also note that the act allows exceptions for safety or administrative reasons. A suspension bridge in the Dry River Wilderness Area in northeastern New Hampshire was rebuilt in 2009 for that reason.

However, a suspension bridge farther downstream on the Pemigewasset River was not replaced after it was removed due to damage in 2010, nor was a nearby beam bridge over Black Brook. Both those decisions, part of what is known as the Pemigewasset Bridge Removal Project, were made to preserve the area’s wilderness aspect and are cited favorably in the draft report.

“Overnight use at Appalachian Mountain Club campsites and huts shows a trend of increased use in the Pemigewasset Wilderness, suggesting the Pemigewasset Bridge Removal Project did not impact visitor use levels. There is no indication that the Pemigewasset Bridge Removal Project in 2009 resulted in an increase in search and rescues; therefore, there would be no cumulative effects to visitor safety resulting from (removing Thoreau Falls Bridge),” the report says.

Comments in the bridge debate must be filed by Sept. 5 via the website at the Pemigewasset Ranger District Office, 71 White Mountain Drive, Campton, or by contacting Abbe by email jabbe@fs.fed.us.

(David Brooks can be reached at 369-3313 or dbrooks@cmonitor.com or on Twitter @GraniteGeek.)