This August 2009 photo shows rock formations at Badlands National Park in South Dakota. The erosion continues, but at a much slower pace than it once occurred. Visitors will surely notice that water can still be found underground. Long ago, water flowing underground eroded the bedrock, forming the cave system. The landscape is unlike the greater Midwest region, including the karst topography known for caves. The park is part of the Driftless Area, which remained glacier-free during the last ice age. Wye Cave, which is not for the faint of heart, can only be accessed by climbing down a 15-foot hole. Dancehall Cave, a nod to the areaвЂ™s historic reputation as a party spot, is the most popular option for exploration because of added walkways and lighting, while some of the 13 caves in the park are only for experienced spelunkers. Grab your headlamps! Northeastern IowaвЂ™s Maquoketa Caves system has been a popular destination for adventurers since the 1860s. Park visitors explore the caves at Iowa's Maquoketa Caves State Park on May, 2, 2010. HiawathaвЂ™s extensive shoreline - which touches Great Lakes Superior, Huron and Michigan - is also dotted with six historic lighthouses, including Port Iroquois Light Station, now a local maritime history museum. Winter brings groomed trails for snowshoeing, snowmobiling and more. In late September, the woods erupt with the reds, oranges and golds of changing leaves and are not to be missed. Summer visitors can hike through biologically diverse forests and rolling sand dunes, or take advantage of the numerous campsites available, including Grand Island, or the quaint and intimate Milkweed Inn ( ), operated by Chicago chef Iliana Regan and sommelier Anna Regan. These days, the natural beauty of MichiganвЂ™s Hiawatha National Forest can be enjoyed year-round. The newly established Civilian Conservation Corps got right to work replanting those trees. Many companies chose to sell land back to the government, which in turn created new national forests. Logging had devastated much of the natural landscape, before the Great Depression stalled work efforts. In the 1930s, MichiganвЂ™s Upper Peninsula would have looked vastly different than it does now. nps.gov/cuvaДЄn Airstream is available for guests to rent on the Milkweed Inn property, owned by the chef Iliana Regan and her wife, Anna Regan, in the Hiawatha National Forest in the Upper Peninsula of Michigan, as seen on Oct. With the Explorer program, you can even flag down a train after a day of exploring, load up your bike or kayak, and get a ride. This is the only nonprofit heritage railroad in the country operating within a national park. The remains of this crucial waterway are a backbone of the park and can be traced by the Towpath trail.ДЇor a truly unique park experience, climb aboard the Cuyahoga Valley Scenic Railroad ( ). When the Ohio and Erie Canal was completed in 1832, connecting local manufacturers with the wider market, the economy boomed. A historic Greek Revival farmhouse, now the bucolic Inn at Brandywine Falls ( ), is a reminder of those early communities.

Locals once utilized the falls and Brandywine Creek to power mills. Brandywine Falls, one of the most idyllic features of the park, is said to have the appearance of a bridal veil as the water rushes over stone. Located along the banks of OhioвЂ™s Cuyahoga River, this national park is under a half-hour drive from Cleveland and Akron, but feels far removed from city life. Cuyahoga Valley National Park is located just 30 minutes from Cleveland.

Backbone trail