Officials are pleading with people to stay away from the area closed off by a wildfire near Harrison Lake.

Fire information officer Noelle Kekula says despite having security personnel watching the road to the area, people are still getting access to it — including boaters who are interfering with helicopter and air tanker operations.

"We're using six helicopters and air support, so we're using the lake as well," she said. "When you've got boats, it's just common sense … We can't use that portion of the lake because we don't want to put public lives at risk."

A helicopter fills a water bucket in Harrison Lake. A fire official says boaters are interfering with these operations. (Chris Corday/CBC)

The area where the fire has been burning since the weekend is home to several rustic campsites. Those sites were ordered evacuated on Sunday.

Kekula said the fire covered 115 hectares as of Tuesday, and was only five per cent contained — unchanged since the day before, when it doubled in size. She said the steep terrain and occasional winds coming off the lake were adding to the difficulty.

An additional 20 firefighters were added to the effort Tuesday, bringing the total number up to 80.

Fire officials say the fire is human caused and under investigation. No property is threatened by the fire.