Colorado Population Density: 27.5 People Per Square Mile (2020)

Colorado's 2020 Census population of 5,773,714 spread across 103,642 sq mi yields 55.7 people per square mile—not 27.5. The 27.5 figure appears to be outdated (closer to 2000 Census: 4.3M/104k = 41.3) or miscalculated.

Density in Context

• National rank: 37th (U.S. average: 94/sq mi)
• Regional: Higher than Wyoming (6), Montana (7), New Mexico (17); lower than Kansas (36), Nebraska (26)
• Extreme skew: Front Range corridor (Fort Collins–Pueblo, 85% of population) >300/sq mi; Western Slope & Eastern Plains <5/sq mi

County Extremes

• Densest: Denver County (4,674/sq mi), Arapahoe (808), Jefferson (758), Adams (482)
• Sparsest: Hinsdale (0.7), Mineral (1.1), Jackson (1.2), San Juan (1.3) — all mountain counties

Growth Dynamics

2010–2020: +14.8% (2nd fastest after Utah). Driven by Front Range migration (tech, lifestyle, cost vs. coasts). Mountain counties growing via remote work; Eastern Plains declining. Projected 2030: ~6.5M.

Why Density Matters

Water allocation (Colorado River Compact), wildfire-urban interface, transportation (I-25 congestion), legislative districting, wildlife corridors. Colorado's "average" density masks two Colorados: urban mountain-front and rural vastness.