BirdAnalyst
Species · Colorado · BBS 2026 Release · 1966–2025

Bald Eagle Population Trend in Colorado

All statesBirds of prey

Bald Eagle in Colorado has risen sharply: up 70% on the route-weighted index since 1984.

+70%Since 1984TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
38Routes In StateSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
28YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Bald Eagle Trends in ColoradoNotable signalsLong-arc shifts the engine flags automatically — sustained declines or increases large enough to stand out from year-to-year noise.Full methodology →

long arc increasecomputed indexTrend sourceWhether the figure is our own computed route-weighted index or an official USGS modeled estimate. The current build labels every trend as computed.Full methodology →

Bald Eagle has risen sharply in Colorado: up 70% on the route-weighted index since 1984.

Bald Eagle Population Forecast in Colorado

If the recent trend holds, Bald Eagle in Colorado is projected to fall about 43% by 2030 — from 0.16 in 2025 to a central estimate of 0.09 (95% range 0.01–0.17). A 5-year backtest shows a typical error of ±47.7%, with 80% of held-out values landing inside the 95% band.

-43%Change by 2030TrendPercent change in the route-weighted abundance index between a smoothed baseline window and the most recent one. It tracks direction, not absolute population.Full methodology →
0.09Projected 2030 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.01–0.1795% range95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
±47.7%Backtest errorBacktest errorTypical error when we hold out the most recent years, forecast them, and compare to what actually happened. Lower means a more trustworthy projection.Full methodology →
If the recent trend holds, Bald Eagle in Colorado is projected to fall about 43% by 2030 — from 0.16 in 2025 to a central estimate of 0.09 (95% range 0.01–0.17). A 5-year backtest shows a typical error of ±47.7%, with 80% of held-out values landing inside the 95% band.19702030
Projection of the recent trend (dashed) with 80/95% bands — a projection, not a prediction. Habitat, climate, and land use are not modeled.
YearProjected indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →95% low95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →95% high95% rangeThe 95% uncertainty band around the projection at the forecast horizon. The true value should land inside it most of the time.Full methodology →
20260.090.000.17
20270.090.000.17
20280.090.010.17
20290.090.010.17
20300.090.010.17

Bald Eagle Survey Routes in Colorado

Routes recording Bald Eagle in Colorado.
Recent countThe raw number of individuals recorded on this route in its most recent survey year. A single-route tally, not a trend.Full methodology →
Buford520252003
Maybell220121970
Dolores219841983
Guffey220252006
Powderhorn220252002
Neegrande220182017
Yampa120212017
Harmony120252019
Arsenal120152001
Arsenal 2120252016
Last Chance120132013
Falfa120232023
Rio Grnds Rs120192016
Wray Gulch120231995
Walden120252015
Lost Lake120252025
Hudson120252016
Wildhorse L120252019
Cortez 2120162010
Animas 2120162015
Tarryall120222022
Castleton120232023
Doyleville120162009
Lay120212016
Nunn120192017

Bald Eagle Population Trend in Other States

alabamaalaskaarizonaarkansascaliforniaconnecticutdelawarefloridageorgiaidahoillinoisindianaiowakansaskentuckylouisianamainemarylandmassachusettsmichiganminnesotamississippimissourimontananebraskanevadanew-hampshirenew-jerseynew-mexiconew-yorknorth-carolinanorth-dakotaohiooklahomaoregonpennsylvaniasouth-carolinasouth-dakotatennesseetexasutahvermontvirginiawashingtonwest-virginiawisconsinwyoming

Source: USGS North American Breeding Bird Survey, retrieved 2026-08-14.