After nearly two million years, the last great Ice Age ended 10,000 years ago. Two-thirds of Ohio had been buried under glaciers, which scoured and shaped the landscape, then covered it with thick layers of glacial till, comprised of sands, gravel, and clay.

In contrast, a third of the state - where the ice didn't reach - remained a rugged, wrinkled land, providing an entirely different home for plant and animal life. Humans have impacted these landscapes as well - clearing, draining, and re-shaping the land to make way for farms, industries, and homes.

Today, Ohio's landscape features five physiographic regions, each with its own geological profile and its distinct communities of plants and animals.

LAKE PLAINS

Once the bottom of a much larger ancient lake known as Lake Maumee, this region is an extremely flat plain
A narrow strip of land along the Lake Erie coast in northeastern Ohio, it broadens significantly west of Cleveland
As water levels rose and fell, sandy beach ridges and dunes formed along the shore
The northwestern area of the region was called the Great Black Swamp - marked by rich, black soils and poor drainage

GLACIATED APPALACHIAN PLATEAU

Carved by glaciers and ancient streams, this region is less hilly and lacks the rugged quality of the unglaciated landscape
Following glaciation, many streams reversed their flow, cutting new paths throughout the region
Evidence of the region's glacial past includes bogs, kettle lakes, and a landscape marked by small hills of sand and gravel called "kames"
Today, the area is marked by smaller tracts of forests, ranging from a few acres to hundreds of acres

TILL PLAINS

This fertile region located south of the Lake Plains is not as flat and is characterized by gently rolling hills
Most hills are a series of moraines, which are glacier-created mounds of rock and soil that are up to 100 feet high and 6 miles wide
A hilly belt of bedrock in Bellefontaine rises 1,549 feet above sea level - the highest point in the state, called Campbell's Hill
Glaciers created terraces along valley sides and new drainage patterns including today's Ohio River

UNGLACIATED APPALACHIAN PLATEAU

Untouched by glaciers, this southeastern Ohio region features deep valleys, high hills and winding streams
Sandstone, resistant to erosion and common in the region, supports a variety of cliffs, gorges, natural bridges and waterfalls
Although the region has thousands of forested acres, the topography is rough and much of the soil is infertile
A long belt of high hills on the eastern edge, running from Monroe to Columbiana County, divides eastward and westward flowing streams

BLUEGRASS

A small, triangular region that reaches up into southern Ohio's Adams County from Kentucky
Flat-topped hills and uplands rimmed by cliffs define the area
Limestone, dolomite and shale bedrock are characteristic of the region and its landscape moves from gentle slopes to steep slopes, depending on erosion
Some uplands are marked by sink holes or depressions that formed in rocks composed mainly of chalk

Selected State Nature Preserves by Physiographic Regions

The Ohio Division of Natural Areas and Preserves is responsible for protecting the best remaining natural areas in Ohio. Most state nature preserves are open daily from dawn to dusk.

LAKE PLAINS- GOLL WOODS

321-acre preserve, near Archbold, Fulton County
Undisturbed remnant of primeval forest in northwestern Ohio, one of the few untimbered remnants of the Black Swamp
Features include giant bur oaks, large white oaks and rich variety of native shrubs and wildflowers, including spotted coral-root and threebirds-orchid
Facilities include parking lot, 5 miles of trail and observation tower

BLUEGRASS - CHAPARRAL PRAIRIE

67-acre preserve, northwest of West Union, Adams County
Outstanding cedar barren prairie with 11 state-listed endangered or threatened plant species, such as prairie false indigo, pink milkwort and Carolina buckthorn
Facilities include .5 mile trail and parking area

GLACIATED APPALACHIAN PLATEAU - KENT BOG

42-acre preserve in Kent, Portage County
Once a glacial kettle lake, the site is now a bog meadow with one of the finest stands of tamarack trees in Ohio
Facilities include parking lot, recycled-plastic boardwalk and interpretative signs

TILL PLAINS - SIEGENTHALER-KAESTNER ESKER

37-acre preserve, northwest of Urbana, Champaign County
Protects a variety of glacial landforms, including eskers, kames, an outwash valley and kettle ponds
Facilities include parking lot and 1 mile of trail

UNGLACIATED APPALACHIAN PLATEAU - ROCKBRIDGE

181-acre preserve, Hocking Hills region, Hocking County
Features Ohio's largest, natural rock bridge, formed from Black Hand sandstone. It spans nearly 100 feet long and arches 50 feet above the rocky ravine
Facilities include parking lot and 2.5 miles of trail