Monday, the popular Trillium Gap Trail begins undergoing a two-year rehabilitation project and access will be closed Monday through Thursday from May 13 to Nov. 15.

The trail will be fully open on Fridays, Saturdays, Sundays and federal holidays.

Trillium Gap Trail is one of the busiest trails in the park because it provides access to the popular Grotto Falls and the summit of Mt. LeConte.

Access to Grotto Falls will be curtailed during the weekday closures. Hikers can still reach Mt. LeConte, LeConte Lodge and the LeConte Shelter from one of four other trails to the summit, including the recently restored Rainbow Falls and Alum Cave trails.

Crews are focusing rehabilitation efforts on several targeted locations along the entire length of the trail stretching from the Rainbow Falls Trail parking area to the summit of Mt. LeConte.

The work will improve overall trail safety and protect natural resources by improving the tread surface, reducing trail braiding, and improving drainage to prevent further erosion, according to the Park Service. Several areas where erosion and small landslides have damaged significant sections make the trail difficult to follow.

Crews will also perform critical work throughout the park, including rehabilitation along Deep Creek Trail, Rough Fork Trail, Smokemont Trail and Noah Bud Ogle Trail.