Description: Detailed large map of Idaho State USA showing cities, towns, county formations, and a light roads layer for orientation.
Map of Idaho (USA). Idaho map with cities, counties, and towns. Use this detailed map to understand Idaho's full county grid, every administrative capital (county seat), the major cities and towns, bordering states and waters, and a few highway cues for orientation only. It is the best map style for residents, travelers, and geography students who want clarity without road clutter. The map follows a natural top-to-bottom sweep, the way you would read an atlas: starting near the Canada border at the top and tracing south along the state outline, then moving west to east across the counties, so the county colors, city dots, and light highway lines line up right where you would expect to find them.
Borders and waters at a glance: This Idaho map with counties and cities shows Canada touching the northern tip, Washington and Oregon bordering the west, Nevada touching the lower left, Utah lining the south center, Wyoming meeting the southeast edge, and Montana running the long eastern border. Idaho has no ocean coast.
Road-light orientation: Only the central spines are useful for placement on this Map of Idaho major cities and interstates. I-84 runs from the Oregon line through Boise, Nampa, and Caldwell, then east to Mountain Home, Twin Falls, and Burley into Utah. I-86 splits near Declo toward American Falls and rejoins I-15 near Pocatello. I-15 runs from Utah through Pocatello, Blackfoot, and Idaho Falls, then north to Montana. I-90 crosses the panhandle through Coeur d'Alene into Montana. US-95 is the long north-south spine from the Canadian line through Sandpoint, Moscow, Lewiston, and Weiser. These help you follow the counties without turning this into a highway list.
This Map of Idaho counties shows a state bordered by Canada to the north, Montana to the east, Wyoming to the southeast, Utah and Nevada to the south, and Oregon and Washington to the west, with no ocean coast. The map shows 44 counties as color blocks, stitched together by I-84, I-86, I-15, I-90, and US-95. Capital and largest city: Boise (Ada County). Largest county by land area: Idaho County, about 8,485 square miles. Smallest county by land area: Payette County, about 408 square miles. Most populous county: Ada County. Least populous county: Clark County. Oldest county: Owyhee County, organized December 1863, the first county formed in Idaho Territory. Total state area: approximately 83,569 square miles, including about 82,643 square miles of land. Largest cities by population: Boise, Meridian, Nampa, Idaho Falls, Caldwell, Pocatello, Coeur d'Alene, Twin Falls, Rexburg, and Post Falls.
Ada–Boise; Adams–Council; Bannock–Pocatello; Bear Lake–Paris; Benewah–St. Maries; Bingham–Blackfoot; Blaine–Hailey; Boise–Idaho City; Bonner–Sandpoint; Bonneville–Idaho Falls; Boundary–Bonners Ferry; Butte–Arco; Camas–Fairfield; Canyon–Caldwell; Caribou–Soda Springs; Cassia–Burley; Clark–Dubois; Clearwater–Orofino; Custer–Challis; Elmore–Mountain Home; Franklin–Preston; Fremont–St. Anthony; Gem–Emmett; Gooding–Gooding; Idaho–Grangeville; Jefferson–Rigby; Jerome–Jerome; Kootenai–Coeur d'Alene; Latah–Moscow; Lemhi–Salmon; Lewis–Nezperce; Lincoln–Shoshone; Madison–Rexburg; Minidoka–Rupert; Nez Perce–Lewiston; Oneida–Malad City; Owyhee–Murphy; Payette–Payette; Power–American Falls; Shoshone–Wallace; Teton–Driggs; Twin Falls–Twin Falls; Valley–Cascade; Washington–Weiser.
Starting at the slim northern tip where Idaho touches British Columbia in Canada, the county right against the border is Boundary County, seat Bonners Ferry, tracked by the Kootenai River. South of Boundary, Bonner County, seat Sandpoint, sits beside the large Lake Pend Oreille, with a highway west toward Spokane and one east climbing into Montana. Immediately south, Kootenai County, seat Coeur d'Alene, is the panhandle's busiest hub, sitting on its namesake lake with I-90 slicing across it toward Spokane to the west and the Silver Valley to the east. Post Falls, one of Idaho's larger cities, sits just west of Coeur d'Alene along the same I-90 corridor.
Southeast of Kootenai, the long county hugging the Montana border is Shoshone County, seat Wallace, home to a string of historic silver-mining towns strung along I-90. South-southwest of there, Benewah County, seat St. Maries, sits along the St. Joe River. West of Benewah, Latah County, seat Moscow, is home to the University of Idaho and sits close to the Washington line, near the US-95 corridor that runs the length of the state.
Moving south, Clearwater County, seat Orofino, includes the Dworshak Reservoir just north of town. West of Clearwater, Nez Perce County, seat Lewiston, sits at Idaho's inland port where the Snake and Clearwater rivers meet, a key junction for US-95 and US-12. Between these two, the smaller Lewis County, seat Nezperce, sits on the Camas Prairie.
Running down the center of the state is Idaho's namesake, Idaho County, seat Grangeville, one of the largest counties in the country outside Alaska, with the Salmon River and its forks tracing the vast, sparsely roaded interior. West of Idaho County, along the Snake River, Adams County, seat Council, sits near New Meadows. Southwest of Adams, Washington County, seat Weiser, sits close to the Oregon line at a US-95 river crossing.
Near the lower left third of the map, the county colors cluster tightly and the road web thickens, marking the Treasure Valley, Idaho's largest metro area. Payette County, seat Payette, sits along the confluence of routes entering from Oregon. Immediately south, Canyon County, seat Caldwell, also includes Nampa. East of Canyon, Ada County, seat Boise, is home to the state capital, with the Boise River and I-84 both running through the valley. North of Boise, Boise County, seat Idaho City, climbs into the mountains, while Gem County, seat Emmett, sits just northwest along a smaller network of feeder roads. South of the Treasure Valley, Owyhee County, seat Murphy, is a huge, sparsely labeled desert county bordering both Oregon and Nevada, where distances between services run long.
Northeast of Boise County, Valley County, seat Cascade, includes McCall and Payette Lake along the Payette River drainage. East of Valley, Custer County, seat Challis, is rugged wilderness country dominated by river gorges and high peaks. On the eastern center of the map, Lemhi County, seat Salmon, hugs the Montana line, with US-93 running north-south through Lost Trail Pass.
Back on the I-84 corridor southeast of Boise, Elmore County, seat Mountain Home, opens toward the Owyhee uplands. East of Elmore, tiny Camas County, seat Fairfield, sits on the Camas Prairie. South of Camas, Gooding County, seat Gooding, and east of it, Jerome County, seat Jerome, sit right along the interstate. Twin Falls County, seat Twin Falls, sits beside the canyon carved by the Snake River near Shoshone Falls. South of the river, Cassia County, seat Burley, borders both Utah and Nevada, and just north, Minidoka County, seat Rupert, sits where I-84 and I-86 split near Declo. At the same latitude but farther east, Blaine County, seat Hailey, holds Ketchum and Sun Valley in the Wood River Valley, and just southeast, Lincoln County, seat Shoshone, rounds out the Magic Valley cluster.
Continuing east on I-84, after American Falls the interstate meets I-15 at Pocatello in Bannock County, seat Pocatello, a key junction with routes leading north to Idaho Falls and south to Utah. Just south of Bannock, Power County, seat American Falls, sits along its namesake reservoir. North of Bannock, Bingham County, seat Blackfoot, and northeast of it, Bonneville County, seat Idaho Falls, follow the Snake River as it arcs around Idaho Falls. Southeast of Bonneville, Caribou County, seat Soda Springs, borders Wyoming. Along the Utah line to the south are Oneida County, seat Malad City; Franklin County, seat Preston; and Bear Lake County, seat Paris, whose largest city, Montpelier, sits near the turquoise waters of Bear Lake. To the north, along the Montana line, thin Clark County, seat Dubois, and southwest of it Butte County, seat Arco, hold sparse rangeland along US-20. Between Bonneville and Fremont, Jefferson County, seat Rigby, and Madison County, seat Rexburg, sit along US-20, while Fremont County, seat St. Anthony, borders both Montana and Wyoming near Yellowstone. East of Madison, Teton County, seat Driggs, presses against the Wyoming line beneath the Teton Range.
Three rivers do most of the orientation work on this map. The Snake River arcs across the southern plain through Twin Falls, Boise, and Idaho Falls before forming part of the Oregon border to the west. The Salmon River loops through the rugged center of the state past Challis and Riggins. The Clearwater River flows out of the panhandle to meet the Snake at Lewiston. Keep these three rivers, plus the interstate system, in mind and any county on the map is easy to place.
I-84: Oregon border to Boise, Nampa, and Caldwell, then to Mountain Home, Jerome, Twin Falls, Burley, and into Utah. I-86: splits near Declo and runs to American Falls, then rejoins I-15 near Pocatello. I-15: Utah to Pocatello, Blackfoot, Idaho Falls, then north to Montana. I-90: Spokane through Coeur d'Alene and the Silver Valley into Montana. US-95: Canada through Bonners Ferry, Sandpoint, Coeur d'Alene, Moscow, Lewiston, Grangeville, and south to the Oregon line.
For residents, travelers, and geography students, a county-first map of Idaho cities and towns gives the most dependable frame for trip planning, permitting, and school district research, since county boundaries define sheriff's offices, road departments, and public lands districts. On this map, the contrasting colors keep each county readable whether the shape is narrow, like Teton, Clark, or Shoshone, or broad, like Idaho County and Owyhee County in the southwest. Stripping out heavy road detail keeps the county lines, seats, and city dots the visual focus, so a quick glance answers the question that matters most: which county is this place actually in.
The Boise metro carries most of Idaho's non-agricultural growth, with Micron Technology's semiconductor plants in Ada County anchoring a tech and manufacturing base that has pulled in suppliers across Canyon and Ada counties. Idaho Falls and Bonneville County lean on nuclear research at the Idaho National Laboratory, while Coeur d'Alene and the panhandle counties draw on tourism, mining heritage, and a steady stream of remote workers relocating from the West Coast. Away from the cities, agriculture still defines most of the map: Idaho grows roughly a third of the nation's potatoes, mostly out of the Snake River Plain counties around Twin Falls, Bingham, and Bonneville, and also ranks among the top producers of trout, barley, and dairy. Idaho's ten largest cities, in order, are Boise, Meridian, Nampa, Idaho Falls, Caldwell, Pocatello, Coeur d'Alene, Twin Falls, Rexburg, and Post Falls, and nearly all of that growth concentrates in the Boise and Coeur d'Alene metro areas rather than spreading evenly across the state.
Sun Valley, in Blaine County, put Idaho on the map as a ski destination back in the 1930s and still anchors the state's resort economy alongside McCall in Valley County. Basque immigrants settled heavily around Boise in the early 1900s, and the city's Basque Block in Ada County is one of the largest Basque cultural centers outside Spain. Moscow, home to the University of Idaho in Latah County, and Pocatello, home to Idaho State University in Bannock County, are the state's two major public-university towns, while Boise State University in Ada County has grown into the largest by enrollment. History runs deep in the panhandle too: Wallace in Shoshone County was a major silver-mining boomtown, and its entire downtown is listed on the National Register of Historic Places. The Nez Perce and Shoshone-Bannock tribes both maintain a strong cultural presence, particularly around Nez Perce County and the Fort Hall Reservation in Bingham and Bannock counties.
On this map, the Snake River Plain, the central mountain belt across Custer, Lemhi, Valley, and Idaho counties, and the lake-rich panhandle in the north double as landmarks for finding counties quickly. For elevation, terrain, watersheds, and land-cover detail, see our Physical Map of Idaho.
Idaho's climate ranges from semi-arid on the Snake River Plain to alpine in the central and panhandle mountains, with cold, snowy winters at higher elevations. For a full seasonal and biome breakdown, see our Physical Map of Idaho.
North to south, US-95 is Idaho's main spine, running the full length of the state from the Canadian border through Coeur d'Alene, Lewiston, and Boise down to the Nevada line, since no single interstate covers the whole state top to bottom. East to west, I-84 carries most of the traffic across the southern counties from the Oregon border through Boise and on to Utah, while I-90 handles the panhandle, linking Coeur d'Alene to Montana. One quick note on the map itself: county lines and ZIP code boundaries don't always match. A single ZIP code can straddle two counties, so use the shaded county blocks on this map for jurisdiction, taxes, and courts, not a ZIP lookup.
Physical Map of Idaho
Physical map and map image of Idaho.
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