BirdAnalyst
Species · Montana · BBS 2025 Release · 1966–2024

Greater Sage-Grouse Population Trend in Montana

All statesGeneralists

Greater Sage-Grouse in Montana has collapsed: down 79% on the route-weighted index since 1971.

-79%Since 1971TrendPercent 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 →
23Routes 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 →
51YearsYears surveyedNumber of years with at least one standard-protocol run in this geography. A longer record makes the trend more reliable.Full methodology →

Notable Greater Sage-Grouse Trends in MontanaNotable 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 declinecomputed 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 →

Greater Sage-Grouse has collapsed in Montana: down 79% on the route-weighted index since 1971.

Greater Sage-Grouse Population Forecast in Montana

If the recent trend holds, Greater Sage-Grouse in Montana is projected to fall about 87% by 2029 — from 0.12 in 2024 to a central estimate of 0.01 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±187.8%, with 100% of held-out values landing inside the 95% band.

-87%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 →
0.01Projected 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 →
0.00–0.7895% 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 →
±187.8%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, Greater Sage-Grouse in Montana is projected to fall about 87% by 2029 — from 0.12 in 2024 to a central estimate of 0.01 (95% range 0.00–0.78). A 5-year backtest shows a typical error of ±187.8%, 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 →
20250.050.000.82
20260.040.000.81
20270.030.000.80
20280.030.000.79
20290.010.000.78

Greater Sage-Grouse Survey Routes in Montana

Routes recording Greater Sage-Grouse in Montana.
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 →
Roy1220211988
Ingomar620241970
Beaverhead519881988
Jordan420171968
Circle419771972
Shawmut419881979
Powderville320241971
Jordan South320212016
Pryor Mtn.220152007
Boulder219711971
St Xavier219881980
Cleveland119871987
Malta120211975
Oswego119831983
Leroy120121980
Brusett120181983
Flatwillow120061970
Forsyth119891988
Laurel119841984
Brandenberg119721968
Albion120121982
Roundup120192016
Miles City120242021

Greater Sage-Grouse Population Trend in Other States

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