ZION NATIONAL PARK, Utah (AP) — Rangers rescued two hikers who were unable to complete one of the more strenuous canyoneering routes at Zion National Park.

The National Park Service says a 41-year-old man and a 26-year-old woman had been hiking for three days when a helicopter crew found them in the lower reaches of Heaps Canyon. They had begun their hike Saturday and had thought they could complete the trek in a day.

Rescuers pulled the pair out of the canyon on Tuesday, after first spotting them Monday.

The route is 11 miles and it involves rappelling and swimming. The Park Service says the hikers had completed two thirds of the hike.

Officials say they were able to rescue the hikers because they spotted their car parked at the trailhead days after they were supposed to be back and they had a backcountry permit with useful information.