TILLAMOOK, Ore. -- The search for two missing campers in a forest east of Tillamook continued to expand Friday, and officials said they hoped weekend visitors could help spot the missing men.

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Friday's search included four agencies and helicopters from the Army National Guard.

On Thursday, Tillamook County Sheriff Andy Long helped with the search from the back of a pickup truck.

"There's a lot of road out here," said Long. "They could be stuck somewhere."

Justin Norton, 35, and Nicholas Santangelo, 53, left their campsite at the Cedar Creek Campground late Monday night to look for some pets that had vanished. They were supposed to return a few hours later.

When they failed to do so, a girlfriend called for help. Authorities were on the ground searching by early Tuesday afternoon.

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"They started hitting all the main forest roads in the area, and there are quite a few in the area," said Sheriff Long. "There's also an off-road vehicle use area, and there's a lot of roads and trails in there."

These roads and trails are the focus. because the men were in Norton's blue, 1998 Ford Explorer when they disappeared. More than two dozen searchers on the ground were joined by a National Guard chopper in the air. It is all very unsettling for other campers.

"What's going on?" Lorena Huerta Branbila asked. "Obviously I'd be concerned if that was my family member."

Both men's families are concerned. Some of them have come out to help with the search. The terrain was described as very steep and thick in some places.

The sheriff pledged to power through.

"It's the beginning of the search," said Sheriff Long. "We are optimistic we can find them."

On Friday, deputies set up tent stations in the campground parking lot to connecting with the influx of weekend campers. They hoped weekend visitors would help the search by keeping an eye out for the missing men.