| Fort Collins insidefortcollins.com | Larimer | 169,810 | 4,997 ft | +18% | About 1 hr 10 min | Poudre School District | The city the other towns measure against: Old Town, the Poudre, CSU and 169,810 people at the 2020 census. |
| Longmont insidelongmontco.com | Boulder & Weld | 98,885 | 4,981 ft | +15% | About 45 min | St. Vrain Valley Schools, the district based in Longmont, whose boundary takes in parts of Boulder and Weld counties; its online lookup gives the neighborhood schools for an address. | The Chicago-Colorado Colony’s 1871 town on the St. Vrain, a city of 98,885 at the 2020 census, with its own fiber network, fifteen miles from Boulder and five from I-25. |
| Loveland insidelovelandco.com | Larimer | 76,378 | 4,997 ft | +14% | About 55 min | Thompson School District R2-J, based in Loveland, which also takes in Berthoud and the Larimer County sides of Johnstown and Windsor. | The Sweetheart City, founded by the railroad on the Big Thompson in 1877: a sculpture garden, a lake in town, and the Centerra interchange on I-25. |
| Castle Rock insidecastlerockco.com | Douglas | 73,158 | 6,224 ft | +52% | — | Douglas County School District RE-1, based in Castle Rock. | The Douglas County seat, 73,158 at the 2020 census, downtown under the rhyolite butte that named it, between Denver and Colorado Springs on I-25. |
| Windsor insidewindsorco.com | Weld & Larimer | 32,716 | 4,797 ft | +75% | About 1 hr | Mostly Weld RE-4 | A sugar-beet town between Fort Collins and Greeley that grew by three-quarters in a decade, with a lake in the middle. |
| Lafayette insidelafayette.com | Boulder | 30,411 | 5,266 ft | +24% | — | Boulder Valley School District. | A former coal town of 30,000 in southeast Boulder County, with an old main street, a lake park and Boulder Valley schools. |
| Erie insideerie.com | Weld & Boulder | 30,038 | 5,072 ft | +66% | About 35 min | Mostly St. Vrain Valley Schools | A coal town that became a commuter town, with a downtown that caught up. |
| Golden insidegolden.com | Jefferson | 20,399 | 5,784 ft | +8% | About 25 min | Jeffco Public Schools, the county-wide district. | A college, brewery and county-seat town at the canyon mouth, twelve miles from downtown Denver. |
| Johnstown insidejohnstown.com | Weld & Larimer | 17,303 | 4,994 ft | +75% | About 50 min | Mostly Weld County School District RE-5J | Sugar-beet town at the I-25 interchange, filling the gap between Loveland and Greeley. |
| Frederick insidefrederickco.com | Weld | 14,513 | 4,938 ft | +67% | About 35 min | St. Vrain Valley Schools, based in Longmont; the Frederick feeder runs from Spark! Discovery Preschool and three elementaries through Thunder Valley K-8 and Coal Ridge Middle to Frederick High. | A coal town on I-25 and Colorado 52 that doubled between the last two censuses, with a six-block old town on Fifth Street. |
| Berthoud insideberthoud.com | Larimer & Weld | 10,332 | 5,033 ft | +102% | About 50 min | Mostly Thompson School District R2-J | The Garden Spot: a real Main Street and the lakes, fifteen minutes from Loveland and Longmont. |
| Evergreen insideevergreenco.com | Jefferson | 9,307 | 7,162 ft | +3% | 30–40 min | Jeffco Public Schools, the county-wide district. | A mountain community at 7,100 feet, unincorporated, with the lake and the elk in the middle of it. |
| Timnath insidetimnath.com | Larimer | 6,487 | 4,869 ft | +938% | About 1 hr | Poudre School District | A farm village that grew tenfold between the 2010 and 2020 censuses, mostly since the Costco. |
| Estes Park insideestespark.com | Larimer | 5,904 | 7,743 ft | +1% | 1 hr 30 min–2 hr | Estes Park School District, the one district for the Estes Valley. | The gateway to Rocky Mountain National Park, at 7,500 feet, with a tourist season and a quiet winter. |
| Manitou Springs insidemanitousprings.com | El Paso | 4,858 | 6,306 ft | −3% | — | Manitou Springs School District 14 | A home rule city of about 4,900 at 6,300 feet at the foot of Pikes Peak, on the west edge of Colorado Springs, with mineral springs and a tourist avenue. |
| Niwot insideniwot.com | Boulder | 4,306 | 5,168 ft | +7% | 45–50 min | St. Vrain Valley School District | Deliberately small and unincorporated: Boulder County and the special districts provide the services, and volunteer groups run the calendar. |
| Clear Creek insideidahosprings.com | Clear Creek | 2,900 | 7,526 ft | +5% | — | Clear Creek School District RE-1, at 320 Highway 103 in Idaho Springs, on a four-day week with optional Enrichment Fridays. Ask about the school assignment and transport for the address. | Two gold and silver towns on the I-70 corridor west of Golden, about 2,900 people together: Idaho Springs on Clear Creek and Georgetown at the head of the valley. |
| Leadville insideleadville.com | Lake | 2,633 | 10,154 ft | +1% | — | Lake County School District | The Lake County seat, a statutory city of about 2,600 at about 10,150 feet, the highest incorporated city in the United States, with a silver-boom main street and long winters. |
| Lyons insidelyons.com | Boulder | 2,209 | 5,341 ft | +9% | About 1 hr | St. Vrain Valley School District | The canyon mouth: sandstone, the river, the music, and a town that rebuilt after the flood. |
| Elizabeth insideelizabeth.com | Elbert | 1,675 | 6,477 ft | +23% | About 1 hr; 45 min to the Tech Center | Elizabeth School District C-1 | Prairie and ponderosa on the Palmer Divide, an hour out and sold five acres at a time. |
| Nederland insidenederland.com | Boulder | 1,471 | 8,235 ft | +2% | About 1 hr | Boulder Valley School District; Nederland Elementary and Nederland Middle-Senior are in town. | A mountain town at 8,200 feet above Boulder Canyon, with Eldora, the Peak to Peak and a bus down the canyon. |