BirdAnalyst
Species · BCR 10 · BBS 2025 Release · 1966–2024

Bald Eagle In Northern Rockies

All regionsNorthern RockiesGeneralists

Bald Eagle in Northern Rockies has surged: up 853% on the route-weighted index since 1983.

+853%Since 1983TrendPercent 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 →
107Routes In RegionSurvey routesHow many standard-protocol BBS routes contributed counts. More routes means a steadier, better-sampled index; very thin coverage is suppressed.Full methodology →
41YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable SignalsNotable 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 surged in Northern Rockies: up 853% on the route-weighted index since 1983.

Bald Eagle In Northern Rockies Population Forecast

If the recent trend holds, Bald Eagle in Northern Rockies is projected to rise about 22% by 2029 — from 0.39 in 2024 to a central estimate of 0.48 (95% range 0.24–0.71). A 5-year backtest shows a typical error of ±33.4%, with 80% of held-out values landing inside the 95% band.

+22%Change by 2029TrendPercent 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 →
0.48Projected 2029 indexProjected indexThe central forecast of the abundance index if the recent trend continues. A projection of the current trajectory, not a prediction.Full methodology →
0.24–0.7195% 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 →
±33.4%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 Northern Rockies is projected to rise about 22% by 2029 — from 0.39 in 2024 to a central estimate of 0.48 (95% range 0.24–0.71). A 5-year backtest shows a typical error of ±33.4%, with 80% of held-out values landing inside the 95% band.19692029
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 →
20250.430.200.67
20260.440.210.68
20270.460.220.69
20280.470.230.70
20290.480.240.71

Routes In Northern Rockies

Routes recording Bald Eagle in Northern Rockies.
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 →
LimaMONTANA112024
CascadeIDAHO81984
Malheur Res.OREGON72023
FontenelleWYOMING62024
Pablo Res.MONTANA52024
HarmonyWYOMING42023
KalispellMONTANA32024
Thompson RivMONTANA32023
GlenMONTANA32023
ChewelahWASHINGTON32021
CurlewWASHINGTON32018
Omak CreekWASHINGTON32024
RiversideWYOMING32023
WalcottWYOMING32024
MaybellCOLORADO22012
NaplesIDAHO22024
Libby DamMONTANA22013
Greenoagh 2MONTANA22008
TroyOREGON22023
UnityOREGON22024
Elk HornWYOMING22015
MammothWYOMING22009
EtheteWYOMING22023
DanielWYOMING21988
BoulderWYOMING22017

Source: USGS North American Breeding Bird Survey, retrieved 2026-05-22.