TIONESTA, Forest County -- Pennsylvania's most sparsely populated county has not a single traffic light, car dealership nor daily newspaper, but it leads the country in one area: recreational homes.

Three of every four dwellings in Forest County are used occasionally, according to the U.S. Census Bureau. This heavily forested northwestern Pennsylvania county has a higher percentage of second homes, cottages or hunting cabins than any other county in the nation, according to Northeast Regional Center for Rural Development at Penn State University.

From late December to early April, Forest County's nearly 5,000 permanent residents lead quiet -- and for many, isolated -- lives on the rolling hills near the Allegheny and Clarion rivers.

But through the spring, summer and hunting season, the residents share their rustic and wild homeland with snowbirds, weekend warriors and other outdoor enthusiasts. Around holidays, such as Labor Day weekend, the county's population triples, said county Commissioner Basil Huffman.

Most of the time, the yearlong residents welcome the visitors because they've made tourism the county's top industry. Other times, there's friction between the people who've settled into a quiet life and the vacationers, Huffman said.

"It's like being 10 feet tall. It's good for some things, but it's not good for others," said John Mehalic, the president of the school board for the Forest County Area School District, where fewer than 700 students were enrolled last year.

One of the reasons for the skewed proportion of recreational homes is that the county doesn't have many dwellings overall -- just more than 8,700 total housing units, according to data from the last census.

Plus, half of the county's 428 square miles is owned by a government entity, said Doug Carlson, the head of the county's Planning Commission and Conservation District. The county sits in the southwest corner of the Allegheny National Forest and state forest, park and game lands cross into its boundaries.

Yet the beauty of the Allegheny Plateau has attracted hunters, anglers and hikers since the 1800s. The land in the county that is available for private ownership has changed hands for decades, Carlson said.

After World War II, farmers began to subdivide their farms, selling plots to middle-class families from Pittsburgh and Youngstown, Ohio, or giving their land to their adult children, Carlson said.

The county's seasonal homes are scattered across the land, sitting next door to permanent residences, said Lon Sebring, the owner of Howard Hanna Shippen Realty's Tionesta Office. Some are settled on the river banks and others are nestled deep in the woods, he said.

Over the years, land owners have constructed everything from one-room log cabins to palatial homes on the wooded plots. In the past, some created a second home out of as little as an old school bus with a hole in the roof for a stove chimney, Carlson said.

But thanks to planning and zoning ordinances, most existing cottages could be yearlong homes and have values that range from $8,000 to $800,000, Sebring said.

Many part-time residents have decided to retire in Forest County and make their seasonal home their permanent residence.

"Quite a [few] people who vacation here say what a beautiful place this is and start looking for land," Huffman said. "Some can't help but stay."