Acadia National Park staff created about 100 feet of rock-lined causeway in two distinct locations on the Cadillac Mountain South Ridge Trail, clearly defining the trail and eliminating the standing water and mud that was there and the hiker encroachment along the trail edges. Before rehabilitation, 87% of hikers stayed on the trail; afterwards this increased to 99%. Observations showed that visitors strayed from the trail largely due to hiker congestion and water, and that the rehabilitation project prevented these behaviors from continuing. We contacted 165 visitors with a subalpine Leave No Trace message. The cost of the project was $7,264 total. The National Park Service and Friends of Acadia match was $4,064, or 56%. The Waterman Fund grant will cover the remaining $3,200.