You can walk through a solid stone arch at this free Indiana preserve

It’s been here 300 million years

Indiana is flat. You know that.

Everybody knows that. But deep in Fountain County, near the Wabash River, a creek has spent millions of years carving a canyon with walls that rise close to 100 feet.

At the bottom of that canyon, a natural stone arch cuts clean through a thick sandstone bluff. Portland Arch Nature Preserve covers 435 acres on the quiet western edge of the state, and it costs nothing to walk in.

The arch is just the beginning of what’s down there.

A stream that carved stone instead of crumbling it

The arch exists because a small stream did something unusual.

It cut into a bluff of Mansfield sandstone from both sides, undercutting the rock little by little over ages. Most of the time, that kind of erosion causes a collapse.

Here, the stone held. What you see today is a natural bridge, solid rock overhead with open air on both sides.

The sandstone dates to the Pennsylvanian age, roughly 299 to 323 million years old. Bear Creek did the rest, carving the deep canyon walls around it.

One of Indiana’s few national natural landmarks

In 1973, the federal government named Portland Arch a National Natural Landmark.

That title goes to places with outstanding geology or plant and animal life, and this preserve earned it for both.

Indiana has more than 160 nature preserves across the state, but only a handful carry that national designation.

The Indiana Department of Natural Resources manages the land today, keeping the trails open and the canyon protected.

You can walk through a place that the government said was worth singling out, and you won’t pay a dime.

The North Trail drops you right to the arch

The North Trail runs about a mile in a loop, and it takes you straight to the arch.

The path dips down between two rocky bluffs, where a wooden boardwalk carries you along the creek and beneath the cliffs. You walk close enough to the rock faces to touch the moss on them.

Then the trail climbs high above the water, giving you a different angle on the canyon before looping back to the start. It’s short, but the elevation changes keep it interesting.

Bear Creek canyon feels 10 times bigger than it looks

Bear Creek runs through a ravine with walls that tower nearly 100 feet on both sides. The water is clear and shallow, winding along the canyon floor where fallen talus rocks rest on the slopes.

You cross the creek on a wooden bridge partway through, and from the bottom, the canyon opens up wide around you. The slow collapse of rock over centuries has shaped everything you see here.

Every boulder along the base got there the hard way.

Moss and ferns grow straight out of the cliff walls

High sandstone bluffs line both sides of the trail, and almost every surface is alive. Mosses, lichens, and liverworts blanket the damp rock faces in green.

Small ferns push out of cracks in the cliffs where you wouldn’t think anything could grow. The layered rock itself tells a story, with patterns left behind by ancient flowing water pressed into the stone.

Native Americans and early pioneers once used the rock shelters here, and you can see why. The overhangs are deep and dry.

Canada blueberry grows here and almost nowhere else in Indiana

Portland Arch holds plants that have no business growing in Indiana. Canada blueberry, rare this far south, survives in the preserve.

So does native bush honeysuckle, another uncommon find. Walk the trails and you pass beds of huckleberry and wintergreen along the ground.

Native white pine, scarce across the state, mixes in with the oaks and hickories overhead.

The cool, shady canyon creates conditions you won’t find in the surrounding farmland, and these plants have held on because of it.

A white oak here is the biggest tree in the preserve

Thick stands of white oak, maple, walnut, and hickory shade both trails. One white oak stands out as the largest known tree in the whole preserve.

In spring, before the canopy fills in, wildflowers cover the forest floor. You can spot Dutchman’s breeches, trout lily, and wood poppy if you time it right.

By summer, the leaf cover is so dense that the ground stays cool and green even on the hottest days. The difference in temperature between the canyon floor and the road above is something you feel right away.

An old dam once powered lights for 16 years

Near the arch, along Bear Creek, you can find the remains of an old dam.

It once held a water wheel and a small power machine that furnished lights for the park for about 16 years. Only the concrete structure still stands today.

It sits quietly in the creek bed, easy to miss if you’re not looking.

The dam is a small reminder that this canyon has drawn people for a long time, and some of them tried to put it to work.

A flatboat once carried Sunday visitors from Lafayette

This spot has pulled people in for more than a century.

Long ago, a flat-bottomed boat carried passengers here from Lafayette on Sundays, floating them down to the canyon for a day out. Later, the land became a Boy Scout camp that ran for nearly 30 years.

In 1966, the Nature Conservancy bought the property to protect it, and by 1972, it became an official state nature preserve. What started as a weekend getaway turned into permanent conservation.

Indigo buntings and catbirds along the South Trail

The South Trail gives you a second mile-long loop through different ground. This one passes through old fields, young woodlands, and lowland forest instead of canyon rock.

Birdwatching draws people here in every season. Cardinals, indigo buntings, gray catbirds, and brown thrashers all move through the trees.

Deer and chipmunks show up along the forest edge, especially in the morning.

If the North Trail is about the geology, the South Trail is about everything that lives on top of it.

Every season changes what the canyon shows you

Spring fills the preserve with wildflowers before the canopy closes. Summer turns the trails into cool, shaded corridors under thick green cover.

Fall paints the oaks and hickories in warm tones that light up the canyon walls.

Winter strips the leaves and reveals the full shape of the sandstone cliffs, letting you see the bones of the place. Crowds stay light all year, so most days you’ll have the trails close to yourself.

That kind of quiet is hard to find.

Hit the trails at Portland Arch Nature Preserve in Indiana

You can visit Portland Arch Nature Preserve in Fountain County, near the small town of Fountain in western Indiana.

Two loop trails, each about a mile long, give you access to the arch, the canyon, and the surrounding forest. The North Trail leads directly to the arch.

Both trails have uneven and sometimes slippery footing, especially when wet, so wear sturdy shoes and stick to the marked paths. Admission is free year-round.

Rock climbing is not allowed, as the cliffs are steep and dangerous.

This article was created with AI assistance and human editing.

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