Teams in eastern Canada have called off an “extensive” six-day air and ground search of a rugged park for a missing Australian hiker.

The Royal Canadian Mounted Police (RCMP) said this week it had suspended operations after an effort involving dogs, 100 people, aircraft and ground crews yielded “no new information” in the whereabouts of Denise Ann Willams.

Williams, 62, has not been heard from since mid April, when she ventured into the Cape Breton Highlands national park. The park, which spans more than 360 square miles, is one of the largest swaths of protected wilderness in the province of Nova Scotia.

Investigators found Williams’ rental car near the head of the Acadian Trail, a 5-mile (8km) loop that gives hikers “panoramic views of the Acadian coastline, the Chéticamp river valley and the park’s highland interior”.

The landscape is riddled with steep cliffs, deep river canyons and extensive boggy areas. Trails can quickly drop into ravines and dense boreal forest.

A sign on the Acadian Trail warns hikers to “be on the lookout for black bear and moose”.

In 2009, Taylor Mitchell, a 19-year-old folk singer, was hiking in the park when she was attacked by coyotes. She called police but succumbed to her injuries. It is the only confirmed fatal coyote attack on an adult human in North America.

RCMP Cpl Mandy Edwards told reporters Williams was hiking alone on an “adventure” vacation, and police had no new information after “exhaustive air and ground efforts over extremely challenging terrain”.

Parks Canada and local search teams often deal with lost hikers, injuries and weather-related disorientation, the result of fast-moving fog off the Atlantic Ocean.

The local teams said they spent little time on the well-marked trails.

“We’re in valleys. We’re in ravines. We’re walking through dense forested areas. We’re walking in areas where there’s a lot of windfalls, so it can be pretty challenging,” Chris Bellemore, the head of a local search and rescue team, told TV station CBC Nova Scotia. “Sometimes you can’t even see your feet from some of the small trees that are growing up and some of the debris that’s on the ground.”

Bellemore said “our hearts go out to her family”, but that the team was still hopeful.

“It’s what’s motivating us to take time off work, to be out there, to be able to try to find a positive outcome to all this,” he said.