Baxter State Park is relocating part of one of its most popular routes up Mount Katahdin in a $102,000 effort that will keep trail crews busy on the slopes of one of Maine’s signature hiking destinations for 18 weeks next year.

A rock slide sent car-sized boulders down Abol Trail in 2013. No one was injured, but the rockfall left the terrain unstable and forced the park to close the route. The new trail to Katahdin’s summit should be finished by autumn 2015.

The work, which will be completed with the help of volunteers, will restore one of the major access routes to the crown jewel of Maine’s hiking landscape. The mountain attracts thousands of hikers a year, many from outside of Maine, and features some of the state’s most spectacular scenery, as well as an unparalleled assortment of rare and endangered species of plants and animals.

The old Abol Trail took a straight path up a 200-year-old landslide, making it the fastest way for hikers to scale to Baxter Peak, Maine’s highest point at 5,268 feet. However, the shorter route was very strenuous, a steep route up loose rock.

Last year, heavy rains caused a slide that sent tons of rocks down the mountain, destroying a mile of the trail.

“There has been little bits of movement every year, but this was big. Rocks the size of cars came down. The original route people would hike was gone and all of the new material that moved is unstable,” Park Director Jensen Bissell said Wednesday. “The old slide’s rocks got set, so it was less likely you’d move a rock and send it down toward hikers below you.”

This year, many hikers used the Katahdin Stream Campground day-use parking area because of the Abol Trail closure.

The new trail, which will be named Abol Trail, leaves from Abol campground and uses the first half of the original trail, which was unharmed by the rock slide. Then, instead of sending hikers up the slide of loose rock, the park will build a trail to the west. This means a slightly longer, but less difficult hike.

The old path was a straight shot at a 38 percent grade for 2.8 miles. The new 3.2-mile trail isn’t quite as steep, with a 27 percent grade, and has some switchbacks – a zig-zag course – along the way. Both the old path and the new trail connect to the Appalachian Trail for a final mile to Baxter Peak.

The new Abol Trail will bring hikers to a ridge with sweeping views of the valley.

“You’re on a ridge line and you have better views all around. There’s a rock cave the trail goes by. You’re looking across the valley, so you can see hikers top out in the tableland,” Bissell said.

Bissell said the old Abol Trail was never technically a trail because it was naturally occurring, not carved by the park’s staff. He does not expect to reopen the original Abol slide, but Bissell said the park won’t tell people not to hike there. If hikers want to take the risk, they can.

Avid hiker Peter Roderick has scaled the old Abol Trail several times in all seasons. He sees the trail relocation as a necessary safety measure.

“I think the new trail will still be a great hike since it is still above treeline for much of its length, which allows great views,” he said. “Switchbacks are not that common in Maine because many mountain trails were originally built for fire tower observers and went straight to the summit.”

Author Henry David Thoreau climbed Katahdin’s Abol slide, adding a history to the old path.

Aaron Megquier, executive director of Friends of Baxter State Park, said things have changed since Thoreau’s days of researching his book “Maine Woods.”

“Early visitors to Katahdin, including Thoreau, presumably chose to climb via the Abol slide because it offered a route that was easier and safer than the alternatives,” Megquier said. “I’m convinced that if Thoreau arrived at the base of the slide now, and saw the car-sized boulders balanced on saplings and loose gravel, he would find another way to get up the mountain. We need to do the same.”

The $102,000 cost of relocating Abol Trail will come from a trust established by Percival P. Baxter, who created the park, as well as revenue from park fees and the sale of wood products. Bissell expects two crews to take about 18 weeks next summer to create the trail by cutting down thousands of small trees and removing the stumps.

The crews also will need to move some rocks to harden the path and to help with drainage. The park will ask for volunteers to help with the work. Park staff began some of the work last season and cleared a couple hundred feet.

“It is a tremendous amount of vegetation to cut and move,” Bissell said. “It’s a big project to do in one season.”