Iowa’s Loess Hills exist in only one other place on Earth and you can explore them free

It’s All Wind-Sculpted Dirt

You’re standing on a ridge in Sioux City, Iowa, looking out over hills that rise 200 feet above the flat plains, and every bit of it is made of dirt. Not rock.

Not sand. Windblown soil, piled up over thousands of years.

The Loess Hills stretch 200 miles along Iowa’s western border, and the only place on Earth with loess deposits this deep and wide is China.

Right in the middle of it all, inside the 1,089-acre Stone State Park, sits the Dorothy Pecaut Nature Center, and it won’t cost you a dime to walk in.

From county farmland to 50,000 visitors a year

The Woodbury County Conservation Board opened the center in 1995 after years of running outdoor education programs in the area.

Two years later, the Pecaut family donated a naming gift to honor Dorothy Pecaut, and the center took her name.

The conservation board had already been teaching environmental education since 1988, so the building gave them a permanent home. In October 2025, the center marked its 30th anniversary.

Today, about 50,000 people come through each year, and they all get in free.

Glaciers melted and wind did the rest

Between 12,500 and 25,000 years ago, glaciers melted and dumped silt across the Missouri River valley floor. Then the wind took over.

Strong gusts picked up that fine silt and carried it east of the river, dropping it layer after layer over thousands of winters. In some spots, the loess runs more than 200 feet deep.

The result is a landscape of sharp ridges, steep bluffs, and yellowish soil so fine that locals call it sugar clay. You can see it crumble in your hands.

Walk under a prairie without getting dirty

Inside the center’s 14,000 square feet, you’ll find a signature exhibit that puts you below ground level, looking up at the root systems of a prairie. It’s one thing to see grass from above.

Seeing it from underneath changes how you think about the whole ecosystem.

Natural history dioramas fill the halls with the plants and animals of the Loess Hills, and a 400-gallon aquarium holds native fish pulled from the region’s rivers and streams.

A live beehive buzzes behind glass, and a bird egg collection lines the wall nearby.

Touch real fossils and meet live owls

The discovery area lets you handle real furs, antlers, and fossils with your own hands.

Two owls, four turtles, and three snakes live at the center as animal ambassadors, and trained naturalists are there to walk you through what you’re seeing.

Programs run year-round, from summer day camps for kids to guided bird-watching hikes for adults. No matter your age, somebody on staff has something lined up for you.

A red-tailed hawk lives just outside the door

The center built an outdoor Raptor House in 2013 to shelter birds of prey that can’t survive in the wild. Residents have included a red-tailed hawk and a barred owl, both permanently injured.

A screech owl also calls the center home. During special events, staff hold live raptor presentations, and the 2025 fall festival included a bald eagle up close.

Bird feeder stations near the building pull in songbirds all year, so you can watch them from just a few feet away.

Let the kids loose in the Discovery Forest

A short walk from the main building, the Discovery Forest Nature Playscape gives kids room to run.

They can climb a tree fort, scramble over logs, and build art from sticks, leaves, and whatever they find on the ground. A water play area lets them wade and splash when the weather cooperates.

The whole setup pushes kids toward unstructured outdoor play, and you’ll probably have to drag them away when it’s time to leave.

Hike past 150-year-old bur oaks on quiet trails

More than two miles of trails wind through the nature center grounds, and they connect to over 10 miles of additional trails inside Stone State Park.

The center’s trails are pedestrian-only, so you won’t share them with bikes or horses. You’ll walk through wooded forests and climb steep prairie ridges with wide-open overlooks.

Bur oak trees along the path have been growing here for more than 150 years, and some of the trunks are thick enough that you can’t wrap your arms around them.

Stone State Park stretches across 1,000 acres next door

The park surrounds the nature center and carries the status of an urban wildlife sanctuary.

The Civilian Conservation Corps built stone entrance portals and the rustic Stone Lodge here in the 1930s, and you can still walk through them.

More than 15 miles of trails cover hiking, mountain biking, horseback riding, and cross-country skiing. From the scenic overlooks, you can see into South Dakota and Nebraska.

The Big Sioux River runs along the park’s western border, and catfish fishing is open to anyone with a line.

Raptors ride thermal updrafts along the bluffs

The Loess Hills sit on a major raptor migration corridor.

Winds off the Great Plains hit the bluffs and push warm air straight up, and hawks and vultures ride those thermals south every fall. Turkey vultures, scarlet tanagers, and whip-poor-wills all show up regularly.

Sioux City earned the title of bird-friendly city in 2024, and the nature center’s feeder stations make spotting songbirds easy. Grab a bench near the feeders and you won’t wait long.

Drive 220 miles of scenic byway through the hills

The nature center sits along the Loess Hills National Scenic Byway, a route the Federal Highway Administration designated as a National Scenic Byway.

The paved main route covers 220 miles from near the Missouri border north to Akron, Iowa, with another 185 miles of optional side loops. You can reach it easily from Interstates 29 and 80.

Along the way, overlooks give you views of the Missouri River valley, forested hills, and grasslands that roll out to the horizon.

Sergeant Floyd died here on the Lewis and Clark trail

The nature center sits along the Lewis and Clark National Historic Trail.

In August 1804, the Corps of Discovery passed through what is now Sioux City and met with the Oto people near this spot. On Aug.

20, 1804, Sergeant Charles Floyd died here, the only member of the expedition to die during the entire journey.

When you walk the trails around the center, you’re looking at a landscape close to what Lewis and Clark would have seen before settlers reshaped the land.

Explore the Dorothy Pecaut Nature Center in Iowa

You can find the Dorothy Pecaut Nature Center at 4500 Sioux River Road in Sioux City, Iowa, inside Stone State Park. The center is open Tuesday through Saturday from 9 a.m. to 4 p.m. and closed on Mondays.

Admission is free. From Interstate 29, take Exit 151 and head north on State Road 12 for about four miles.

Check the official website before you go to confirm hours and see what programs are running during your visit.

This article was created with AI assistance and human editing.

Read more from this brand:

• A 200-mile ribbon of ice-age silt makes this Iowa road one of Earth’s rarest drives
• Lose yourself in 1.2 million acres of caves, rivers, and bluffs in the Arkansas Ozarks
• This lakeside Minnesota town is quietly outclassing every coastal village in New England