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

Osprey In Northern Rockies

All regionsNorthern RockiesGeneralists

Osprey in Northern Rockies has risen sharply: up 53% on the route-weighted index since 1970.

+53%Since 1970TrendPercent 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 →
112Routes 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 →
56YearsYears 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 →

Osprey has risen sharply in Northern Rockies: up 53% on the route-weighted index since 1970.

Osprey In Northern Rockies Population Forecast

If the recent trend holds, Osprey in Northern Rockies is projected to rise about 37% by 2029 — from 0.28 in 2024 to a central estimate of 0.39 (95% range 0.17–0.61). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.

+37%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 →
0.39Projected 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 →
0.17–0.6195% 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 →
±50.5%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, Osprey in Northern Rockies is projected to rise about 37% by 2029 — from 0.28 in 2024 to a central estimate of 0.39 (95% range 0.17–0.61). A 5-year backtest shows a typical error of ±50.5%, with 100% of held-out values landing inside the 95% band.19682029
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 →
20250.380.150.60
20260.380.160.60
20270.380.160.61
20280.390.160.61
20290.390.170.61

Routes In Northern Rockies

Routes recording Osprey 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 →
CascadeIDAHO131984
WilsonWYOMING52024
CentervilleIDAHO42019
NezperceIDAHO32012
CabartonIDAHO32023
SunbeamIDAHO32017
ClintonMONTANA32024
LaurierWASHINGTON32022
MammothWYOMING32010
NaplesIDAHO22021
MivodenIDAHO22018
Lolo PassIDAHO22014
Cape HornIDAHO22024
CoolinIDAHO22021
Sawtooth CtyIDAHO22009
PierceIDAHO21992
Libby DamMONTANA22012
St MaryMONTANA22007
St. Mary 2MONTANA22024
Hebgen LakeMONTANA22024
VictorMONTANA22019
GraniteOREGON22004
TwickenhamOREGON22024
OttoWYOMING22008
BasinWYOMING22023

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