Every ZIP code in the United States, with weather, radar, trivia and the numbers behind it. Five digits since 1963!

ZIP stands for Zone Improvement Plan. The codes went live on July 1, 1963.The lowest ZIP code is 00501 — the IRS in Holtsville, New York.The highest ZIP code is 99950, in Ketchikan, Alaska.Type 07734 into a calculator and turn it upside down: hELLO. It is Keansburg, New Jersey.12345 belongs to one company: General Electric in Schenectady, New York.The first digit is a region: 0 is New England and New Jersey, 9 is the West Coast, Alaska and Hawaii.Mr. ZIP, the cartoon mailman, was the mascot that sold the idea to America.ZIP+4 arrived in 1983 and can narrow a ZIP down to one side of one block.A ZIP code is a mail route, not a place: plenty of them cross county and even state lines.Play ZIP Hunt: guess the secret ZIP code of the day in six tries.
zipcodes.pro — RANKINGS/ID/LARGEST-AREA

Largest ZIP Codes in Idaho by Land Area

What this measures. Land area of the Census tabulation area, in square miles. Water is excluded. Source: Census Gazetteer, data release 2026-10-12.

# ZIP City County Land area
1 83611 Cascade Valley 2,678.76 sq mi
2 83539 Kooskia Idaho 2,084.36 sq mi
3 83226 Challis Custer 2,010.38 sq mi
4 83278 Stanley Custer 1,635.68 sq mi
5 83647 Mountain Home Elmore 1,504.53 sq mi
6 83650 Murphy Owyhee 1,455.97 sq mi
7 83469 Shoup Lemhi 1,336.47 sq mi
8 83342 Malta Cassia 1,228.82 sq mi
9 83464 Leadore Lemhi 1,140.10 sq mi
10 83251 Mackay Custer 1,124.15 sq mi
11 83716 Boise Elmore 1,039.09 sq mi
12 83244 Howe Butte 888.92 sq mi
13 83805 Bonners Ferry Boundary 880.06 sq mi
14 83327 Fairfield Camas 849.72 sq mi
15 83467 Salmon Lemhi 843.77 sq mi
16 83604 Bruneau Owyhee 793.73 sq mi
17 83211 American Falls Power 743.42 sq mi
18 83252 Malad City Oneida 736.39 sq mi
19 83221 Blackfoot Bingham 725.61 sq mi
20 83276 Soda Springs Caribou 693.69 sq mi
21 83213 Arco Butte 676.78 sq mi
22 83638 McCall Valley 668.40 sq mi
23 83525 Elk City Idaho 577.78 sq mi
24 83254 Montpelier Bear Lake 558.35 sq mi
25 83340 Ketchum Blaine 557.70 sq mi
26 83423 Dubois Clark 549.92 sq mi
27 83672 Weiser Washington 545.70 sq mi
28 83549 Riggins Idaho 535.61 sq mi
29 83333 Hailey Blaine 520.60 sq mi
30 83612 Council Adams 497.19 sq mi
31 83429 Island Park Fremont 494.60 sq mi
32 83610 Cambridge Washington 484.63 sq mi
33 83861 Saint Maries Benewah 456.45 sq mi
34 83637 Lowman Boise 454.97 sq mi
35 83522 Cottonwood Idaho 437.31 sq mi
36 83320 Carey Blaine 418.26 sq mi
37 83645 Midvale Washington 416.95 sq mi
38 83263 Preston Franklin 413.86 sq mi
39 83420 Ashton Fremont 410.77 sq mi
40 83677 Yellow Pine Valley 406.48 sq mi
41 83864 Sandpoint Bonner 402.20 sq mi
42 83856 Priest River Bonner 396.93 sq mi
43 83530 Grangeville Idaho 390.30 sq mi
44 83253 May Lemhi 388.62 sq mi
45 83654 New Meadows Adams 377.48 sq mi
46 83302 Rogerson Twin Falls 351.92 sq mi
47 83346 Oakley Cassia 308.55 sq mi
48 83445 Saint Anthony Fremont 300.74 sq mi
49 83217 Bancroft Caribou 299.54 sq mi
50 83301 Twin Falls Twin Falls 295.69 sq mi

Showing the top 50 of 279 ZIP codes in Idaho that have this figure and meet the threshold above. 83611 ranks 1st at 2,678.76 sq mi, against 295.69 sq mi in 50th place.

Other rankings for Idaho

Cite this page

zipcodes.pro. “Largest ZIP Codes in Idaho by Land Area.” Data release 2026-10-12. Retrieved 2026-10-20. https://zipcodes.pro/rankings/id/largest-area

Underlying data is public domain or openly licensed — sources, vintages and licences.