Search crews continued the hunt on Friday for a 20-year-old Toronto woman missing in the woods near Thunder Bay, Ont.

Christina Calayca went missing Monday during a camping trip to Rainbow Falls Provincial Park.

The Ontario Provincial Police have more than 570 hectares of terrain to cover and are using search dogs, helicopters, marine units and civilian volunteers to cover the area, which is 200 kilometres east of Thunder Bay.

"This is probably the most rugged terrain in northwestern Ontario," OPP Supt. Mike Armstrong told CTV News on Friday.

"We're talking cliffs in places 600 to 800 feet high, so it's a very difficult area to search with a very dense tree canopy, which makes the search from the air hampered."

Officers say they don't suspect foul play in Calayca's disappearance and are following some leads.

Police say Calayca was camping with her 20-year-old first cousin, Faith Castulo, and two men she knew from a Christian youth group when she decided to go for a jog in the woods at 6:30 a.m.

Authorities suspect the woman lost her way in the bush.

The woman is not an experienced camper and told family members she was heading to Montreal with friends for the holiday weekend.

Calayca's family is baffled by her disappearance and the circumstances surrounding her camping trip.

Her aunt, Mary Restua, says the family is praying for Calayca's safe return.

"We don't want to think negative, we just hope that she will come back to us and we will find her," Restua told CTV News on Friday.

Her mother and five uncles have since made the trek to Thunder Bay to be closer to the search.

Calayca, a daycare worker in the Parliament and Wellesley Streets area, was last seen wearing a blue-hooded sweatshirt and black pants.

The OPP maintain it's not uncommon for people to be found unharmed after surviving several days in the woods.

Experts recommend if anyone finds themselves lost in the woods, they should stay in one spot and not panic.

With a report from CTV's Naomi Parness