Idaho Counties Map: Click All 44 Counties

How many counties are in Idaho?

Idaho has 44 counties. 31 states have more, and 18 have fewer.

Idaho has 44 counties. The largest is Idaho County, which stretches across the narrow middle of the state from Oregon to Montana. Ada County, home to Boise, has the most people.

How Idaho's counties were formed

Idaho Territory was organized in 1863, and its first legislature created the early counties, including Ada (1864), home to Boise. Mining, railroads and irrigation farming on the Snake River Plain set off waves of county-making, and 1910s splits added many of the newest counties. Caribou County, created in 1919, was the 44th and last.

Idaho regions and the counties in each

Idaho is often taught in regions. North Idaho, the Panhandle, holds Boundary, Bonner, Kootenai (Coeur d'Alene) and Shoshone counties. North Central Idaho takes in Nez Perce (Lewiston), Latah and Idaho counties. Southwest Idaho is the Treasure Valley around Boise: Ada, Canyon, Payette and Gem. The Magic Valley in south-central Idaho centers on Twin Falls, and Eastern Idaho includes Bonneville (Idaho Falls), Bannock (Pocatello) and Fremont, which touches Yellowstone.

Notable places on the Idaho county map

Borah Peak, the state's highest point at 12,662 feet, is in Custer County. Craters of the Moon National Monument protects lava fields in Butte and Blaine counties, and Hells Canyon, deeper than the Grand Canyon, follows the Snake River along the Oregon border in Idaho and Adams counties. Shoshone Falls, on the Snake River at Twin Falls, drops 212 feet, higher than Niagara Falls.

Idaho counties map: the biggest and smallest

Idaho County is the largest county in Idaho, with 8,478 square miles of land, about 10% of the state. That's more land than 6 whole states, including Connecticut, Delaware, Hawaii and others. Payette County is the smallest, at 407 square miles.

The smallest counties by land area are Payette County (407 sq mi), Teton County (449 sq mi) and Madison County (469 sq mi).

Which counties in Idaho have the most people?

Ada County has the most people, about 535,799 in the Census Bureau's July 2024 estimate, or 27% of everyone in Idaho. The three biggest counties together hold 50% of the state's 2,001,619 people. Clark County has the fewest, about 794.

The most crowded is Ada County, with about 509 people per square mile. The emptiest is Clark County, with less than one person per square mile. Comparing the two is a quick way to show children that a big county on the map isn't always a big county in people.

What county is Boise in?

Boise, the capital of Idaho, is in Ada County. It's also the county with the most people. Idaho is called the Gem State, and it became the 43rd state in 1890.

Counties on the Idaho border

Learning the edge of the map first gives children a frame to fill in. Idaho shares a border with Montana, Nevada, Oregon, Utah, Washington and Wyoming.

How Idaho's counties compare with other states

Idaho ranks 11th among the 50 states in land area and 38th in population. Its average county covers about 1,878 square miles and holds about 45,491 people. Across the 50 states, the average county-level area covers about 1,139 square miles and holds about 109,381 people, so Idaho's counties are bigger than usual in size. Bigger counties mean fewer names to learn for a state this size.

Landmarks for learning the counties of Idaho

• The skinny northern Panhandle counties (Boundary, Bonner, Kootenai) touch Canada.
• The Snake River Plain curves across the southern counties from Idaho Falls to Boise.
• Idaho County spans the middle of the state where it is narrowest.

With 44 counties, work one region at a time: study it with names on, then take a Practice round and stop when you've found that group. Then print the Idaho county map worksheet to check that it sticks on paper.

All 44 Idaho counties

Every county on the map, A to Z, with its land area and July 2024 population estimate.

Idaho geography for homeschoolers

Pair this map with the West states and capitals quiz and the US states quiz. If you teach at home, see homeschooling in idaho, and check idaho school choice to see whether a program may help pay for Idaho history and geography curriculum. Each program decides what it covers.