Wisconsin is often described as flat, frozen, and famous for cheese. The state’s geography and history include several lesser-known facts that contradict that simple image. Its landscape contains an ancient mountain range, more lakes than Minnesota, and rock formations that predate complex animal life. Even the state’s name has an origin unrelated to the animal.

Geologists named the most recent North American ice age the Wisconsin glaciation because the state preserves the clearest evidence of that period. About 15,000 years ago, ice sheets more than a mile thick covered the land. The drumlins, kettle lakes, and moraine ridges left behind are considered the most complete record of the glacial era.

The state’s geological history goes back much further. Around a billion years ago, a rift tore through the continent and nearly split it in two. The rift stalled, but left behind basalt formations visible in the Saint Croix River gorges. The oldest rock in Wisconsin, found near Wisconsin Rapids, is about 3.268 billion years old. That rock formed before oxygen filled the atmosphere and before complex life existed.

The Wisconsin Dells, now known for its water parks, was carved in a short period. When a glacial lake larger than Lake Ontario broke through its ice dam, the floodwaters cut a canyon through solid sandstone in days. A region called the Driftless Area in southwestern Wisconsin was missed by glaciers entirely. It remains a jagged, pre-glacial landscape of valleys and ridges that has eroded for millions of years.

Wisconsin has more than 15,000 documented lakes, more than Minnesota. Door County, a peninsula in the northeastern part of the state, has 250 miles of shoreline, more than any other county in the United States. The Niagara escarpment, a limestone ridge running through eastern Wisconsin, is the same formation that creates Niagara Falls in New York. Wisconsin also borders two Great Lakes, Lake Superior and Lake Michigan, and includes the Apostle Islands in Lake Superior.

A marker in Ripon sits at the intersection of the 45th parallel and the 90th meridian, the midpoint between the equator and the North Pole and between the prime meridian and the international dateline. Only four such intersections exist on Earth. One is in Wisconsin.

The Republican Party was founded in a schoolhouse in Ripon in 1854 by anti-slavery activists. In 1871, the same night as the Great Chicago Fire, a wildfire in Peshtigo killed up to 2,500 people, making it the deadliest wildfire in recorded American history. The event received little attention at the time because Peshtigo lacked the press infrastructure that Chicago had.

The Green Bay Packers are the only nonprofit, publicly owned professional sports team in the United States. The team cannot be relocated because it has no individual owner. The Baraboo Range in south-central Wisconsin is among the oldest exposed rock in North America, with peaks about 1.6 billion years old. Harley-Davidson motorcycles began in a small shed in Milwaukee in 1903. The first practical typewriter was built in Milwaukee in 1867, and its QWERTY keyboard layout is still used today.

Wisconsin was the first state to vote to end prohibition enforcement within its borders. The Wisconsin Dells now has the highest concentration of water parks in the world. The ice cream sundae is credited to a soda fountain in Two Rivers in 1881. The Ringling brothers launched their circus in Baraboo in 1884.

The state’s nickname comes from lead miners in the 1820s who dug crude shelters into hillsides rather than building permanent homes. Those burrows led to the “badgers” nickname. In 1962, a fragment of the Soviet satellite Sputnik 4 landed on a street in Manitowoc. The US government returned it to the USSR under international treaty. The first American kindergarten was established in Watertown in 1856. Marathon County grows about 95 percent of commercially grown American ginseng.

Northern Wisconsin lakes contain floating peat and moss islands large enough to support trees. The Apostle Islands sea caves transform into ice formations during the coldest winters. Cave of the Mounds, discovered in 1939, is a limestone cave whose formations grow slowly, taking about 150 years to deposit a single cubic inch of calcite. Big Manitou Falls in Pattison State Park drops 165 feet, nearly the same height as Niagara Falls. A Mississippian culture built an ancient stockaded city called Aztalan in southeastern Wisconsin about a thousand years ago, with earthen pyramids and plazas aligned to astronomical events.

Wisconsin’s sandstone contains volcanic ash from eruptions 450 million years ago on the East Coast. In 1862, geologists identified the first fossil reef formally classified in North America in a Milwaukee suburb, a coral formation from when Wisconsin sat near the equator in a tropical sea. The Hodag, a mythical creature invented by a lumberjack in 1893, is now the official symbol of Rhinelander. The House on the Rock, built atop a 60-foot rock chimney, includes a glass corridor extending over a valley. The National Mustard Museum in Middleton holds more than 6,000 jars of mustard. The Ice Age Trail traces the boundary of the last glacier across the state.

The Kickapoo River is among the most winding rivers in North America. Thousands of drumlins across Wisconsin point in the direction the ice traveled. Lake Superior’s cold water preserves shipwrecks because the temperature is too low for the organisms that decompose wood. The Kettle Moraine in eastern Wisconsin is considered one of the most complex glacial landscapes in the world.

Many of Wisconsin’s rivers flow above ancient channels filled by glacial debris. Ground penetrating radar has found entire drainage systems hundreds of feet underground. The Saint Croix River Dalles contain cylindrical shafts drilled into bedrock by glacial meltwater. Glacial Lake Wisconsin, larger than modern Lake Ontario, once covered central Wisconsin until its ice dam failed. The state is 46 percent forested, with 16 million acres of forest cover. Devil’s Lake, enclosed by quartzite bluffs, has no surface inlet or outlet and is fed by underground springs.

Wisconsin’s geology preserved the most complete record of the last ice age, which is why scientists named an entire chapter of Earth’s history after it. The state’s landscape, though often seen as flat and unremarkable, holds a detailed history of the continent’s geological and human past.