State Border Quiz: Which State Borders Iowa and Montana?

Quiz challenge

Which state shares land borders with both Iowa and Montana?

A Minnesota B North Dakota C Nebraska D South Dakota

Select an answer to continue.

Map enthusiasts and geography lovers know that U.S. state borders form fascinating geometric patterns across North America. While many Midwestern and Great Plains states share boundaries with multiple neighbors, only one state in the region stretches far enough east to touch Iowa while reaching northwest all the way to Montana. Unraveling this boundary puzzle requires a quick mental tour of the northern plains.

The correct answer

D) South Dakota

South Dakota is the state that shares land borders with both Iowa and Montana.

Located in the northern Great Plains, South Dakota is bordered by six states in total. To its northwest lies Montana, where the two states meet along a shared boundary in Harding County, South Dakota, and Fallon and Carter counties, Montana. Farther east and south, South Dakota extends across the Missouri River and fertile plains to share a land and river border with Iowa at its southeastern corner, near Sioux Falls. Because of its expansive east-to-west stretch across the northern plains, South Dakota bridges the geographical transition from the Upper Midwest to the Mountain West.

Why each choice fits—or doesn’t

A) Minnesota

Why it is not the answer: Minnesota borders Iowa to its south, Wisconsin to its east, North Dakota and South Dakota to its west, and Canada to its north. However, Minnesota is separated from Montana by the entire width of North Dakota, making this option incorrect.

B) North Dakota

Why it is not the answer: North Dakota borders Montana to its west, South Dakota to its south, Minnesota to its east, and Canada to its north. While it does touch Montana, North Dakota does not reach Iowa, as South Dakota sits directly between North Dakota and Iowa's northern border.

C) Nebraska

Why it is not the answer: Nebraska borders Iowa to its east, South Dakota to its north, Wyoming and Colorado to its west, and Kansas and Missouri to its south. Although it touches Iowa along the Missouri River, Nebraska does not touch Montana, as South Dakota and Wyoming sit directly north and northwest of Nebraska.

D) South Dakota

Correct choice: South Dakota is the correct choice because its expansive borders touch six states: North Dakota to the north, Minnesota to the east, Iowa to the southeast, Nebraska to the south, Wyoming to the west, and Montana to the northwest.

More context

South Dakota's unique geographic position plays a key role in connecting different physical regions of the United States. The state is physically split into two distinct geographic and cultural halves by the Missouri River, often referred to locally as East River and West River. The eastern region features low prairie land, glacial lakes, and rich agricultural soils typical of the Upper Midwest, linking naturally with western Iowa and southwestern Minnesota. The western region features rolling plains, dramatic badlands, and the elevated granite uplift of the Black Hills, sharing rugged terrain and historic ranching traditions with eastern Montana and Wyoming. Additionally, South Dakota holds the distinction of containing the geographic center of the entire 50 United States, located near Belle Fourche in the northwest corner of the state, just east of its border with Wyoming and southeast of Montana.

Quick facts

South Dakota borders six states in total: North Dakota, Minnesota, Iowa, Nebraska, Wyoming, and Montana.
The geographic center of all 50 U.S. states is located in Butte County, South Dakota, north of Belle Fourche.
The Missouri River bisects South Dakota into eastern prairie lowlands and western high plains.
Harding County in northwestern South Dakota shares borders with both Montana and North Dakota.
South Dakota became the 40th state admitted to the Union on November 2, 1889, alongside North Dakota.

Sources

South Dakota – Census Bureau — U.S. Census Bureau South Dakota shares land borders with six states, including Iowa to the southeast and Montana to the northwest.
South Dakota summary — Encyclopædia Britannica South Dakota is bordered on the north by North Dakota, east by Minnesota and Iowa, south by Nebraska, and west by Wyoming and Montana.