This remarkable pocket of land along the Illinois River includes 18 sandstone canyons; 14 waterfalls; abundant wildlife and birds; Belle of the Rock paddleboat excursions; and guided hikes, special events and interpretive programs. The free guided hikes are a great way to see the highlights of Starved Rock State Park. If you're up for more exploration, also visit neighboring Matthiessen State Park, where 5 miles of trails carve into the mile-long canyon, passing rocks, waterfalls and beautiful, sometimes dizzying, vantage points.
At 71,000 acres, Custer State Park (30 miles south of Rapid City) is one of the nation's largest state parks, known for granite spires called Needles and the 1,500 head of bison that wander freely. You can't go wrong with any of the trails here, but for a short, 1-mile walk, it's hard to beat the loop around lovely Sylvan Lake. For a longer hike, head to Harney Peak (and into the Black Hills National Forest); it's about 7 miles round-trip from the Sylvan Lake trailhead, with gorgeous vistas of the area's famous granite formations.
The Hocking Hills region attracts outdoor enthusiasts with its trails that lead through forests to caves and rock formations. At Hocking Hills State Park (55 miles southeast of Columbus), hikers find sweeping overlooks, fern-filled valleys and shelf caves. Favorite trails for fall foliage include Cedar Falls, Old Man's Cave, Ash Cave and the Grandma Gatewood Trail. Nearby Hocking State Forest and Conkle's Hollow State Nature Preserve also offer spectacular fall vistas.
The Porkies (150 miles west of Marquette) embody Michigan's remote Upper Peninsula, with 59,000 wild acres, 90 miles of trails and, if you get away from the campsites, not too many visitors. If you only go once, be sure to stop and drop your jaw at the Lake of the Clouds vistas, ringed in fall by a necklace of color. Porcupine Mountains Wilderness State Park also claims dozens of waterfalls, including a spectacular series easily accessible along the half-mile boardwalk of the Presque Isle River Scenic Area.
The peaceful vistas alone warrant a day trip to Indiana's largest state park (60 miles south of Indianapolis), but resort-style extras make Brown County State Park a full-fledged destination. The great on-site stable offers horseback trips and pony rides, and the restaurant-lodge includes a new indoor water park. More than 18 miles of hiking and mountain bike trails spread over the area, winding around hills and beside streams. Fall scenery also unfolds from nearly 20 miles of tree-lined roads.
The country's largest tallgrass prairie dominates the east-central section of Kansas and includes 22 counties. The Tallgrass Prairie National Preserve, established in 1996, is the only unit of the national park system dedicated to the rich natural and cultural history of this kind of ecosystem. In autumn, the plains' searing summer is past and prairie grasses are peaking. Trails wind through scenic vistas, prairie grasses and rugged terrain. Rangers offer daily guided tours of an 1881 ranch house, as well as bus tours of the preserve, May-October.
North of Duluth on State-61, the turnoffs for fabulous state parks come one after another, like Burma Shave signs flashing past your window: Gooseberry Falls (pictured), Split Rock Lighthouse, Tettegouche. All told, eight parks sit along the North Shore, loaded with waterfalls, forest trails and achingly beautiful Lake Superior views.
Also in the area, woods dotted with maples flaming red and orange attract visitors to the 277-mile Superior Hiking Trail. Less adventuresome travelers can take a leisurely ride to panoramic views on the mountain tram in Sawtooth Mountain Park or just drive the North Shore Scenic Drive (State-61), which runs 150 miles from Duluth at the southwestern tip of the lake to Grand Portage at the Canadian border.
Sprawling more than 33,000 acres, the Horicon Marsh in central Wisconsin is the largest freshwater cattail marsh in the United States and one of the largest in the world. Come fall, it's a haven for hundreds of thousands of migrating ducks and Canada geese. Explore it via a 50-mile auto tour encircling the marsh, or experience it by bike, boat or foot (trails include a floating boardwalk!). A visitors center and education center offer displays, maps and other information on the marsh; guided wildlife and birding hikes are available in fall.
Horicon Marsh 
Mississippi and Wisconsin river views unfold from trails in Pikes Peak State Park (65 miles northwest of Dubuque). Stand on a 500-foot bluff overlooking the confluence of the rivers, walk past spring-fed streams and waterfalls, or wander through large wooded tracts cloaked in fall colors of red and gold. The park borders the small town of McGregor (population: 876), a onetime steamboat port.
Fall brings dustings of yellow and orange to the 70,000 acres of painted canyons and grassy hiking trails that border Interstate-94 and the Little Missouri River. Bison graze along the road, and prairie dogs chatter at scenic turnouts. Theodore Roosevelt National Park features two large units 50 miles apart, separated by the small Roosevelt's Elkhorn Ranch. The southern unit, anchored by nearby Medora, is busier and has more trails of varying skill levels, but the northern is just as spectacular.
Garden of the Gods, in southern Illinois, is a 3,300-acre national recreation area in Shawnee National Forest. View towering rock outcroppings just south of where great ice sheets smoothed the prairies millions of years ago. Hike along 5.5 miles of trails; an easy flagstone Observation Trail takes you to a spectacular overlook.
Larger than New York's Central Park and chock-full of activities, this sprawling 1,293 acres attracts locals and visitors. Tour Forest Park by foot, bicycle, boat or even Segway. Free attractions in the park include the Saint Louis Zoo, with lush landscaping perfect for enjoying on a fall day. If you visit during the Great Forest Park Balloon Race in September, rent a pedal boat and watch the balloons drift through a cloudless sky from your floating perch in the Grand Basin.
Forest Park 
Indiana's best all-around park (65 miles west of Indianapolis) has a large lodge; hiking trails through deep, wooded ravines; horseback riding; hayrides; and an impressive, year-round lineup of naturalist programming, including walks, history talks and live-animal presentations. For fall color, stretch your legs on any of Turkey Run State Park's 11 trails -- from a half-mile to 3 miles long -- that lead through gorges, past geological landmarks and to historical sites such as the 1848 Colonel Lieber Cabin.
Mackinac Island State Park surprises visitors with its faraway-woods feel, despite being a few hundred yards from downtown. More than 80 percent of Mackinac Island is within the state park. Hike, bike or ride a horse through forests, past geological formations and along limestone bluffs. One of our favorites: Tranquil Bluff Trail, which traces the eastern shore, where red, brown and golden leaves drift down from a canopy of red oaks, beeches and maples.
Hiking, biking, boating, fishing, camping, golf, a nature center and the historic Eagle Bluff lighthouse are among the highlights of Peninsula State Park, one of the most popular destinations in Door County. Visit the nature center for fall program information. The Sunset Trail, a 9.6-mile gravel route, is a great introduction to the park; the relatively flat trail begins at the Fish Creek entrance and winds along the western and northern part of the park, through forest, over marsh and rarely far from the waters of Green Bay. The trail is open to bikes, wheelchairs and foot traffic.
Peninsula State Park 
A web of steep trails loops over the sandstone cliffs along Pease Creek at Ledges State Park, 40 miles northwest of Des Moines. Take an easy stroll along Canyon Road (currently closed to cars), or hike up several trails that wind up the canyon sides, including ones that lead to a rocky overlook of the Des Moines River. The trail around Lost Lake is flatter, but fall colors flutter in the breeze there as well.
Ledges State Park 
Along the Missouri River bluffs in northeastern Nebraska, Ponca State Park spreads out over almost 2,400 acres of heavily forested hills and Missouri River bottomland. Activities include a rich lineup of outdoor education programs and 20 miles of varied hiking trails. The park's annual Hallowfest in October offers fall fun with haunted hayrack rides, a campsite-decorating contest, pumpkin rolling and carving contests, and more.
Ponca State Park 
The Edge of Appalachia Preserve could be considered the crown jewel of Adams County's parks. The 13,500-acre sanctuary, run by the Nature Conservancy and the Cincinnati Museum Center, offers three hiking trails, including Buzzardroost Rock, but most of The Edge lies untouched. Roughly 1,200 plant species grow here, many rare or endangered. Like Adams County itself, the preserve feels blessedly undiscovered -- it rewards explorers more than tourists.
Fall color arrives as early as September along the Mississippi River in the Twin Cities. Popular Minnehaha Park, off the Grand Rounds National Scenic Byway, draws visitors with its 53-foot waterfall, river overlooks and shaded trails, all in a tidy 193-acre space. When you're ready to move on, visit some of the other parks and lakes accessible from the 55-mile Grand Rounds National Scenic Byway, the country's only official urban scenic byway.
Minnehaha Park 
In Cleveland, you can have your nature and your city, too. Just 20 minutes from downtown is Cuyahoga Valley National Park, a 33,000-acre preserve. Where mules once pulled canal boats, walkers and bicyclists now stream along the 20-mile Ohio and Erie Canal Towpath Trail. More ambitious hikers choose from an additional 100 miles of trails. Families tour a 19th-century living history museum, and the Cuyahoga Valley Scenic Railroad chugs past heron and bald eagle nests (and offers ghost train rides in autumn!).
Roads and trails weave through this bluff-top park north of Grafton overlooking the Illinois River near its meeting of the Mississippi. The renovated Civilian Conservation Corps-built lodge, with fried chicken dinners and a massive lobby fireplace, is an area fall-drive destination. At 8,050 acres, Pere Marquette is Illinois' largest state park and offers 12 miles of hiking trails, as well as horseback riding and camping. Bird-watching is popular during fall migration season.
This 3,000-acre park in southeast Nebraska (80 miles south of Omaha) offers 20 miles of hiking trails through hardwood forests known for their brilliant fall colors. The Missouri River curves through Indian Cave State Park along sandstone bluffs marked with hollows and caves. The rugged area is popular with hikers, campers and backpackers.
Choosing between Minnesota and Wisconsin's Interstate state parks feels a little like asking a mother which child she prefers. A mom can't play favorites, but we can. The parks face off across the St. Croix River. Both offer cool hikes by rocky glacial potholes, but the larger Wisconsin park (50 miles northeast of Saint Paul) also has a large lake, a heron rookery and a wildlife trail. If you want to visit both, the US-8 bridge links the parks.
Midwest Living's Facebook fans also suggested these destinations:
• Backbone State Park, west of Dubuque, Iowa: "Great overlooks and fall color" (pictured).
• Copper Falls State Park in Mellen, Wisconsin: "Dramatic waterfalls and gorges, so fabulous in fall."
• Newton Hills State Park in Canton, South Dakota: "A beautiful park with lots of oaks. Great color!"
• Jubilee State Park near Brimfield, Illinois.
• The Dawes Arboretum in Newark, Ohio: "Beautiful!"
• Central Park in Carthage, Missouri.
• Hartwick Pines State Park near Grayling, Michigan: "40-plus acres of old-growth forest."
• Castle Rock State Park in Oregon, Illinois: "Beautiful in the fall."
• Nichols Arboretum, Ann Arbor, Michigan.
• Pictured Rocks National Lakeshore, Munising, Michigan.
• Boulder Junction, Wisconsin: "The whole area is a park. Boulder Junction is surrounded by 225,000 acres of the Northern Highland-American Legion State Forest, and driving any of the surrounding roads bordered with numerous lakes is beyond spectacular any time of the year, but especially in the fall!"
Backbone State Park 
Jubilee State Park 
The Dawes Arboretum 
Carthage's Central Park 
Castle Rock State Park 
Nichols Arboretum