America's national park areas have a reputation for being heavily used, but 90 percent of the visitors show up at only 30 percent of the parks. The less-visited parks often are little-known or just plain hard to get to.

For whatever reason, here are 12 of the nation's undervisited national park areas:

* Yukon-Charley Rivers National Preserve, Alaska: A 130-mile stretch of the Yukon River.

* Kobuk Valley National Park, Alaska: The Kobuk River and the Great Kobuk Sand Dunes of northern Alaska.

* Alibates National Monument, Texas: Ancient Indian flint quarries in the northern Panhandle.

* Fort Bowie National Historic Site, Arizona: Site of military operations against Geronimo and Cochise of the Chiricahua Apaches in southeastern Arizona.

* Fort Jefferson National Monument, Florida: An island fortress in the Dry Tortugas 70 miles west of Key West.

* Knife River Indian Villages National Historic Site, North Dakota: Remnants of five Plains Indian villages, once visited by Lewis and Clark.

* Noatak National Preserve, Alaska: Noatak River basin and the 65-mile Grand Canyon of the Noatak in northern Alaska.

* Voyageurs National Park, Minnesota: The water route of the French-Canadian voyageurs on the Canadian border.

* Pecos National Monument, New Mexico: Ruins of the ancient Pecos pueblo and a Spanish mission and church on the Santa Fe Trail southeast of Santa Fe.

* Jewell Cave National Monument, South Dakota: Gleaming limestone caverns linked by narrow passages in southwest South Dakota.

* Big Bend National Park, Texas: Mountain scenery at the great bend of the Rio Grande River in southwestern Texas.

* Pictured Rocks National Lakeshore, Michigan: Cliffs, beaches and dunes on the Upper Peninsula, America's first "national lakeshore."