How to read this map
Cluster colors
- 🔴 Red — high incident density (5+ reports)
- 🟠 Orange — medium density (2–4 reports)
- 🟢 Green — lower density or isolated incident
Status types
- Confirmed — USDA-verified depredation permit or loss report
- Suspected — Rancher-reported, pending verification
- Historical — Pre-2019 documented records
Using the filters
- Use Seasonal Context to see eagle presence by time of year — Spring (Mar–May) is peak lambing risk
- Use Data Type to isolate confirmed losses vs. all reported incidents
- Click any marker for incident details and source links
847
Recorded incidents across 11 western states
3,400+
Estimated sheep lost in Wyoming in 2024
76%
Of eagle losses are 2–4-week-old lambs
Mar–May
Peak lambing — peak eagle pressure
Live Hotspot
Sublette County, WY — 14 confirmed incidents this spring · Peak lambing risk window active
Report an Incident →
🔴 Depredation Severity
Critical — Heaviest documented losses
High — 10+ ranches with confirmed kills
Moderate — Occasional incidents
Low — Migration corridor, limited ranching
🏗️ Eagle Nesting Density
Highest — Wyoming, 800+ territories
Very High — CO, OR, NV, ID
High — CA Diablo, MT, NE NM
⚡ Electrocution Hotspots
Highest — Bighorn Basin, WY (480+ documented)
Very high — SW Wyoming & Uinta Basin
High — SW Colorado
⚡ ~500 golden eagles electrocuted per year in the U.S. (~26% of human-caused deaths). Layer is off by default — enable it under "View Layers" above.
🦅 Migration Corridors
Spring (Mar–Apr) — Northbound, dispersed
Fall East (Sep–Nov) — Rocky Mtn Front, 43% of migrants
Fall West — Secondary BC/WA route
📊 Data Layers
Eagle population — Breeding pairs (size = count)
Sheep density — State-level flock size
eBird sightings — Verified eagle observations
Wind turbines — Major western wind farms
📍 User-Submitted Reports
10+ animals lost in single incident
5–9 animals lost
1–4 animals lost
💡 Tip: Marker size on ranch pins = flock size. Click any marker for details. Use the layer toggles below to show/hide categories.
⚠️ Vulnerability Index by State (combines sheep density + eagle presence + timing)
🚨 Critical Impact: Wyoming
3,400+
Estimated sheep lost in 2024 (USDA NASS). 83% of ranches report eagle depredation. Golden eagles concentrated after migration.
💰 Economic Impact
$48K
Single ranch loss (SW Montana, 1 season). At $222/head market value, losses across all states exceed $2 million annually.
🐑 Sheep at Risk
2.8M
Breeding ewes in western USA. Texas (670K), California (510K), Colorado (405K) have largest concentrations.
USDA Livestock Data 2025
🎯 Most Vulnerable
2-4 weeks
Lamb age. Represent 76% of predation losses. Spring lambing (March-May) = peak risk period. Juveniles/subadult eagles hunt lambs most aggressively.
Total Population
31,800
Interior-western U.S. golden eagle population estimate. Wyoming has ~3,778 estimated breeding pairs - highest concentration. Population is roughly stable range-wide, with local declines in some regions.
USFWS, data through 2016
✅ Solution Available
3,800+
Licensed falconers in USA. Non-lethal capture & relocation is 69% more cost-effective than lethal control.
🏔️ Alaska: Significant Eagle Population
~13,000
Estimated golden eagles statewide (a conservative count, roughly a few thousand breeding pairs) — one of North America's larger golden eagle populations. Interior Alaska alone has ~1,200 estimated breeding pairs. Mat-Su Valley domestic sheep ranchers face severe spring lambing pressure with minimal USDA support.
🏗️ Golden Eagle Nesting Hotspots
3,500+
Active nesting territories across western USA. Wyoming (804 documented nest territories), Colorado (500), Oregon (506) are densest. Nests 3.1-8.2 km apart in optimal habitat.
USFW Nesting Survey Data
🏢 Texas Impact
338
Ranches reporting eagle depredation. Highest ranch count affected. 38,000 sheep/lambs lost to all predators (includes eagles).
📍 Montana Hotspot
SW MT
Southwestern Montana (Dillon area) documented as severe. Documented losses: $48,000 on 2 adjacent ranches. Eagles concentrate on lambing operations.
🛣️ Migration Corridor
Peak Sep-Nov
Rocky Mountain Front. Up to 43% of fall migrants concentrate in this single corridor (Bedrosian et al. 2018). Fall routes are more concentrated and extend farther south into Wyoming than spring routes — opposite of what was previously assumed.
📡 Data Source
VERIFIED
USDA ADC records, USFW survey data, field research, Wyoming Public Media 2020 study, ASI reports, state wildlife agencies.
2019-2025 Recent Data
🚨 The Spring Lambing Crisis
Problem: March-May is peak lambing season AND when golden eagles return from winter. Lambs age 2-4 weeks are most vulnerable.
Impact: Wyoming lost an estimated 3,400+ sheep in 2024. A single Montana ranch lost $48,000 in one season. Eagles (especially juveniles/subadults) kill lambs at sunrise when dispersed from protection.
Why It Matters: Most predation occurs on open-range operations where lambs lack protective cover (brush, woods, sheds). Timing is critical - 76% of eagle-caused losses are 2-4 week old lambs.
Solution: Non-lethal capture and relocation by licensed falconers proven 85% effective at reducing losses. Increasing availability across western states.
This is not hypothetical - documented cases from Wyoming, Montana, Colorado, Texas, Utah, Idaho, New Mexico.
Understanding the Map
🏗️ Golden Eagle Nesting Concentrations
HIGHEST - Wyoming (804 documented nest territories, 20+ pairs/1000km²)
VERY HIGH - Colorado (500), Oregon (506), Nevada (430), Idaho (156)
HIGH - California Diablo Range (230 pairs), Montana (115), NE New Mexico (123)
MODERATE - Arizona, Idaho, Washington, South Dakota
Territory Size: 3-65 sq miles per pair. Spacing: 3.1-8.2 km between nests. Overlaps directly with sheep ranching areas.
🔴 Depredation Zones (Severity)
CRITICAL - 338+ ranches (Texas), 3,400+ sheep lost (Wyoming 2024, est.)
HIGH - Documented losses, 10+ ranches affected (Montana, Colorado, Utah)
MODERATE - Occasional incidents, migration areas (Idaho, New Mexico)
LOW - Eagle migration corridors, limited ranching
🔴 Migration Corridors
Spring Route (mid-Mar – early Apr) — More dispersed northbound movement to breeding grounds
Fall Eastern Route (mid-Sep – early Nov) — Concentrated southbound, extends farther into Wyoming. Up to 43% of all fall migrants use this single corridor (Bedrosian et al. 2018)
Fall Western Route (mid-Sep – early Nov) — Secondary route via eastern BC/Washington, reconverges with eastern route in spring
Primary Corridor: Rocky Mountain Front ecotone (BC/Yukon → Montana → Wyoming). Southern Wyoming hosts the highest intersection of wind development potential and peak eagle migration density (Bedrosian et al. 2018, PLOS ONE).
Eagle Population (Green)
Breeding pairs by state (sized by population)
Wyoming: ~3,778 estimated breeding pairs (highest). Roughly stable range-wide, with local declines in some regions.
🐑 Sheep Density
State sheep population (lighter = fewer sheep, darker = more sheep)
Texas: 670K sheep. California: 510K. Colorado: 405K. Open-range operations = highest predation risk.
🏢 Individual Sheep Ranches (200+)
CRITICAL RISK - Frank Shirts (28K), Helle Rambouillet (10K), others
HIGH RISK - 1,000-4,000 sheep operations
MODERATE RISK - 500-1,500 sheep operations
Marker size = flock size. Click for ranch details, location, acres, operation type, and specialist contacts.
💙 Observations (Blue Dashed)
eBird sightings (verified eagle presence and activity)
Data Sources:
| Layer | Source | Year | Link |
|---|---|---|---|
| Depredation | USDA APHIS Wildlife Services — Program Data Reports | 2019–2022 | View Reports → |
| Wyoming Survey | Wyoming Public Media — "When Sheep Become An Eagle's Diet" | May 2020 | Read Article → |
| ASI Reports | American Sheep Industry Association — Industry data & policy | Ongoing | sheepusa.org → |
| Migration Corridors | Bedrosian et al. (2018) PLOS ONE — "Migration corridors of adult Golden Eagles originating in NW North America" — 64 adult eagles, 6 study areas (Teton Raptor Center, Raptor View Research Institute, ADF&G), 53 spring + 54 fall routes via dBBMM | 2011–2016 | View Study → |
| Migration Counts | Rocky Mountain Eagle Research Foundation — Annual raptor migration counts, Kananaskis, Alberta | 1992–present | eaglewatch.ca → |
| Eagle Population | USFWS Eagle Population Status & Management | 2016–2024 | fws.gov → |
| ND Nest Data | North Dakota Game & Fish / USFWS Statewide Nest Database (600 known sites; 139 active) | 2014 | ndgf.gov → |
| Sheep Density | USDA NASS — Sheep & Goat Inventory (January 2025) | Jan 2025 | nass.usda.gov → |
| Sightings (eBird) | eBird Status & Trends — Golden Eagle abundance & range models | 2023–2026 | ebird.org → |
Confidence Levels: CRITICAL = Verified field data & government records · HIGH = Well-documented studies · MODERATE = Confirmed incidents · LOW = Estimated / migration zones
🔬 Migration Corridor Citation: Route lines and corridor descriptions reflect Bedrosian, B.E., et al. (2018). "Migration corridors of adult Golden Eagles originating in northwestern North America." PLOS ONE 13(11), e0205204. DOI: 10.1371/journal.pone.0205204. Study tracked 64 adult eagles from 6 study areas (Teton Raptor Center + Raptor View Research Institute + Alaska Dept. of Fish & Game) via dBBMM, 2011–2016. Key finding: fall routes are more concentrated than spring routes and best-predicted wind resources in the western U.S. directly overlap the Rocky Mountain Front corridor.