CO · 2026 Census Gazetteer

Colorado counties by area

Official, comparable measurements for 64 counties and county equivalents.

Source fields preservedGEOID · ALAND · AWATER

County equivalents64

Combined land103,637.3 mi²

Combined water457.6 mi²

Largest by landLas Animas County

Understanding Colorado’s county areas

The land-area range runs from Broomfield County at 33 mi² to Las Animas County at 4,772.9 mi². The largest has 144.8 times the land area of the smallest and accounts for 4.6% of the combined county land in Colorado.

The median county-equivalent land area is 1,431.5 mi², above the national median of 604.5 mi². The median describes the middle of the county size distribution; it does not describe how people or development are distributed. A state with a few very large counties can have a much smaller median than its largest entry suggests.

Where water changes the picture

Larimer County has the most assigned water area, at 38.2 mi². Boulder County has the highest water share, with water making up 1.9% of its total area. Water area and water percentage answer different questions: the first measures an amount, while the second measures the mix of land and water.

Across all 64 entries, water accounts for 0.4% of the combined total area. This is calculated from the summed land and water measurements, rather than averaging county percentages, which would give each small and large county equal weight.

Compare the largest and smallest county equivalents in Colorado to see land, water, and total area on the same scale.

These calculations use the 2026 Census county records listed below. County-equivalent boundaries vary between states; area alone does not measure population, density, or usable land. See coverage and calculation rules.

Complete area table

Sorted from largest to smallest land area.

#	County / equivalent	Land	Water	Water share
1	Las Animas CountyGEOID 08071	4,772.9 mi²	2.7 mi²	0.1%
2	Moffat CountyGEOID 08081	4,743.3 mi²	7.6 mi²	0.2%
3	Weld CountyGEOID 08123	3,985 mi²	31.8 mi²	0.8%
4	Mesa CountyGEOID 08077	3,328.7 mi²	12.4 mi²	0.4%
5	Gunnison CountyGEOID 08051	3,239.1 mi²	20.5 mi²	0.6%
6	Rio Blanco CountyGEOID 08103	3,221 mi²	1.9 mi²	0.1%
7	Saguache CountyGEOID 08109	3,168.6 mi²	1.7 mi²	0.1%
8	Garfield CountyGEOID 08045	2,947.4 mi²	8.4 mi²	0.3%
9	Larimer CountyGEOID 08069	2,595.7 mi²	38.2 mi²	1.5%
10	Lincoln CountyGEOID 08073	2,577.7 mi²	8.8 mi²	0.3%
11	Baca CountyGEOID 08009	2,555 mi²	2.4 mi²	0.1%
12	Washington CountyGEOID 08121	2,518.1 mi²	5.9 mi²	0.2%
13	Pueblo CountyGEOID 08101	2,386.6 mi²	11.2 mi²	0.5%
14	Yuma CountyGEOID 08125	2,364.4 mi²	4.3 mi²	0.2%
15	Routt CountyGEOID 08107	2,362 mi²	6.1 mi²	0.3%
16	Montrose CountyGEOID 08085	2,240.9 mi²	1.9 mi²	0.1%
17	Park CountyGEOID 08093	2,193.5 mi²	16.8 mi²	0.8%
18	Kit Carson CountyGEOID 08063	2,160.8 mi²	0.9 mi²	0%
19	El Paso CountyGEOID 08041	2,126.4 mi²	2.7 mi²	0.1%
20	Montezuma CountyGEOID 08083	2,029.3 mi²	10.5 mi²	0.5%
21	Elbert CountyGEOID 08039	1,850.8 mi²	0.2 mi²	0%
22	Grand CountyGEOID 08049	1,846.6 mi²	23 mi²	1.2%
23	Logan CountyGEOID 08075	1,838.6 mi²	6.3 mi²	0.3%
24	Cheyenne CountyGEOID 08017	1,778.3 mi²	3.2 mi²	0.2%
25	Kiowa CountyGEOID 08061	1,767.8 mi²	18.2 mi²	1%
26	La Plata CountyGEOID 08067	1,689.7 mi²	9.9 mi²	0.6%
27	Eagle CountyGEOID 08037	1,684.5 mi²	7.3 mi²	0.4%
28	Prowers CountyGEOID 08099	1,638.4 mi²	5.9 mi²	0.4%
29	Jackson CountyGEOID 08057	1,613.7 mi²	7.2 mi²	0.4%
30	Huerfano CountyGEOID 08055	1,591 mi²	2.2 mi²	0.1%
31	Fremont CountyGEOID 08043	1,533.8 mi²	0.9 mi²	0.1%
32	Bent CountyGEOID 08011	1,512.8 mi²	28.2 mi²	1.8%
33	Archuleta CountyGEOID 08007	1,350.1 mi²	5.3 mi²	0.4%
34	Conejos CountyGEOID 08021	1,287.4 mi²	3.6 mi²	0.3%
35	San Miguel CountyGEOID 08113	1,286.7 mi²	2 mi²	0.2%
36	Morgan CountyGEOID 08087	1,280.5 mi²	13.4 mi²	1%
37	Otero CountyGEOID 08089	1,261.9 mi²	7.8 mi²	0.6%
38	Costilla CountyGEOID 08023	1,227.6 mi²	3.4 mi²	0.3%
39	Adams CountyGEOID 08001	1,166.8 mi²	16.8 mi²	1.4%
40	Delta CountyGEOID 08029	1,142.1 mi²	6.5 mi²	0.6%
41	Hinsdale CountyGEOID 08053	1,117.2 mi²	5.9 mi²	0.5%
42	Dolores CountyGEOID 08033	1,067.2 mi²	1 mi²	0.1%
43	Chaffee CountyGEOID 08015	1,013.4 mi²	1.5 mi²	0.2%
44	Pitkin CountyGEOID 08097	970.7 mi²	2.5 mi²	0.3%
45	Rio Grande CountyGEOID 08105	912 mi²	0.4 mi²	0%
46	Mineral CountyGEOID 08079	875.8 mi²	2 mi²	0.2%
47	Douglas CountyGEOID 08035	840.1 mi²	2.6 mi²	0.3%
48	Arapahoe CountyGEOID 08005	797.9 mi²	7.6 mi²	0.9%
49	Crowley CountyGEOID 08025	787.4 mi²	12.9 mi²	1.6%
50	Jefferson CountyGEOID 08059	764.4 mi²	9.7 mi²	1.3%
51	Custer CountyGEOID 08027	738.6 mi²	1.3 mi²	0.2%
52	Boulder CountyGEOID 08013	726.4 mi²	14.1 mi²	1.9%
53	Alamosa CountyGEOID 08003	722.6 mi²	0.6 mi²	0.1%
54	Phillips CountyGEOID 08095	687.9 mi²	0.1 mi²	0%
55	Summit CountyGEOID 08117	608.3 mi²	10.9 mi²	1.8%
56	Teller CountyGEOID 08119	557.1 mi²	1.9 mi²	0.3%
57	Sedgwick CountyGEOID 08115	548 mi²	1.4 mi²	0.2%
58	Ouray CountyGEOID 08091	540.7 mi²	1.5 mi²	0.3%
59	Clear Creek CountyGEOID 08019	395.1 mi²	1.3 mi²	0.3%
60	San Juan CountyGEOID 08111	387.5 mi²	0.8 mi²	0.2%
61	Lake CountyGEOID 08065	376.9 mi²	7 mi²	1.8%
62	Denver CountyGEOID 08031	153.1 mi²	1.7 mi²	1.1%
63	Gilpin CountyGEOID 08047	150 mi²	0.4 mi²	0.2%
64	Broomfield CountyGEOID 08014	33 mi²	0.6 mi²	1.7%

How to read this table. Land and water areas are Census statistical measurements in square miles. Adding county rows can differ slightly from separately published state totals because of rounding and geographic treatment.