Physical Geography

IowaIowa is a state in the Midwestern region of the United States.

Iowa lies within the Central Lowlands region of the United States and consists mostly of flat to rolling land. Glaciers shaped most of the terrain by laying down thick deposits of debris, called drift, during the last Ice Age. In some places they left distinct topographic features, largest of which are the till plains of mixed clays, sands, gravels, and boulders. Also of glacial origin are thick deposits of compacted silt, called loess, which cover large areas.

North-central Iowa is the flattest part of the state. Southern and western Iowa consists mostly of rolling to hilly land. The northeast is a hilly area that was virtually untouched by glaciers, and consequently, has been subjected to erosion over a long period of time. High bluffs line some of Iowa's rivers, particularly the Missouri and the Mississippi.

The highest point in Iowa, 1,670 feet (509 m), is in the northwest; the lowest point, 480 feet (146 m), is in the southeast on the Mississippi River.

IowaIowa state tree - Oak

All the rivers of Iowa are part of the Mississippi River drainage system. They flow either southeastward to the Mississippi itself or southwestward to the Missouri, the Mississippi's chief tributary. The largest rivers within the state are the Des Moines and the Iowa, which flow to the Mississippi.

Numerous small lakes of glacial origin dot north-central Iowa. Several large artificial lakes, including Rathbun, Red Rock, and Saylorville, have been impounded, primarily for recreational use and flood control.


Iowa has a continental climate, with hot summers and cold winters. July temperatures average near 75° F. (24° C.) throughout the state and normally reach daily highs of 85° to 90° F. (29° to 32° C.). January temperatures average about 14° to 22° F. (-10° to -6° C.), increasing from north to south. Daily lows during January are normally between 8° and 18° F. (-13° and -8° C.).

Annual precipitation ranges from about 25 inches (635 mm) in the west to 35 inches Thomas Hovland/Grant Heilman Photography (890 mm) in the east. Most of the precipitation is in the form of rain, falling mainly during spring and summer. Snowfall is moderate throughout the state.

Blizzards, tornadoes, and hailstorms occasionally strike the state.


Most of Iowa was originally grassland; forests probably occupied only about 15 per cent of the land. Today, most of the state's land is used for farming; virtually nothing remains of the grassland, and forests cover only about 4 per cent of the state. Nearly all the forested area consists of privately owned woodlots on farms, mostly in the eastern part of the state. More than 70 species of trees are native to Iowa; virtually all are hardwoods. Oaks, maples, and hickories are among the chief trees.

IowaIowa state flower - wild rose
Interesting facts about Iowa
"Go West, young man, go West and grow up with the country!" was Horace Greeley's famous advice to Josiah Bushnell Grinnell in 1853. A year later, Grinnell, a Congregationalist minister, left New York City. He settled on a prairie between the Iowa and Skunk rivers and established the town of Grinnell.
The Pottawattamie County jail in Council Bluffs was a unique three-story prison sometimes referred to as "the human squirrel cage" or "lazy Susan jail." Pie-shaped cells at the jail rotated around a central core. The core had only one opening on each floor. Once a prisoner entered a cell from the core, the cell was rotated by a crank, leaving the cell completely sealed off. The structure was used as a jail from 1885 until 1969. It has since been restored and is open for viewing by the public.
The shortest and steepest railroad in the United States is located in Dubuque. The track is 296 feet (90 meters) long and rises at an incline of 60 degrees to a height of 189 feet (58 meters). The railroad was built in 1882 by a local banker, J. K. Graves. It still operates today and is called the Fenelon Place Elevator.
The red Delicious apple, the top-selling apple in the United States, was developed on an orchard near East Peru. Shoots from the stump of a stray apple tree began producing fruit on Jesse Hiatt's orchard in the 1880's. Hiatt entered the new variety, which he called the "Hawkeye" apple, in an apple contest and won. In 1895, Stark Brothers Nursery purchased rights to the apple, renaming it Delicious. Offshoots of the original tree still produce apples on the same site.
The Kate Shelley Bridge was named after a heroic Iowan who saved hundreds of lives through her courage. During a storm in the summer of 1881, teen-ager Kate Shelley heard a crash near her home in Boone County, Iowa. A railroad bridge had collapsed, and a small switch locomotive lay in a creek below. Kate knew an express passenger train was due shortly, and she hurried to the nearest station at Moingona. She made a dangerous crossing of the railroad bridge over the rushing Des Moines River and arrived at the station in time for a railway crew to stop the passenger train. Parades were held in Kate's honor, and streets and parks throughout the state were named for her. When the Chicago and NorthWestern Railway built a new bridge over the Des Moines River in 1901, they named it the Kate Shelley Bridge. The bridge is one of the highest and longest double-track bridges in the world and still stands today.