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Pathfinder Reservoir

Natrona County, WyomingView mapDirections

Wyoming DEQ publishes the water-quality measurements for Pathfinder Reservoir. Here is what has been measured.

Phosphorus
10 µg/L
Measured by Wyoming DEQ
Trend
Stable
5 years of samples
  • Public access
  • Limited data

Ask about Pathfinder Reservoir

Answers come straight from the public measurements and survey records on this page.

Pathfinder Reservoir in Natrona County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Phosphorus: 10 µg/L.

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Pathfinder Reservoir is a lake in Natrona County, Wyoming. Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Wyoming DEQ, last sampled 2015-09-23. Grade methodology: LakeQuality methodology.

What Pathfinder Reservoir is good for

From access and monitoring records, not editorial picks.

  • Boat launch1 documented ramp

Swimming conditions

No reading

Limited data

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Pathfinder Reservoir is safe to swim in today is a call for the Wyoming Department of Environmental Quality and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Pathfinder Reservoir

These are the measurements Wyoming DEQ publishes for Pathfinder Reservoir, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data. Phosphorus 10 µg/L. TSI 37.

MetricValueEPA condition class
Water Clarity (Secchi Depth)No recent samples
Phosphorus10 µg/LMeasured, not scored
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)37Oligotrophic

Low nutrients, clear water. No reading is a swimming clearance.

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Pathfinder ReservoirPublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Fishing Pathfinder Reservoir

Based on 5 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Phosphorus Stable+0.23 µg/L/yr5
See year-by-year chart →

Reservoir Info (USACE NID)

Pathfinder Reservoir is a man-made reservoir impounded by the Pathfinder Dike (completed 1911), built primarily for fish and wildlife pond on the North Platte River Offstream; earth-type dam, 38 ft tall and 1,650 ft long.

Normal storage
1,016,500 ac-ft
Max storage
1,016,500 ac-ft
Hazard class
High
Owner
BUREAU OF RECLAMATION

All listed purposes: Fish and Wildlife Pond;Irrigation;Hydroelectric;Water Supply.

Source: USACE National Inventory of Dams, NID ID WY01295 · Operator website

Nearby Lakes in Natrona County

Frequently asked questions about Pathfinder Reservoir

Where is Pathfinder Reservoir?

Pathfinder Reservoir is a lake in Natrona County, Wyoming. Its water-quality measurements are published by Wyoming DEQ and shown on this page as reported.

What is the water quality of Pathfinder Reservoir?

Pathfinder Reservoir in Natrona County, Wyoming has water-quality measurements published by Wyoming DEQ, shown here as reported. Phosphorus: 10 µg/L.

Is Pathfinder Reservoir safe to swim in?

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Are there boat ramps on Pathfinder Reservoir?

Pathfinder Reservoir has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Pathfinder Reservoir. Public access is listed as yes.

Where this data comes from

1 measurement from 1 monitoring station, 2015. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • State of Wyoming Department of Environmental Quality Watershed ProgramWYDEQ_WATERSHED1 sample · 2015

Analytical methods

  • Total Phosphorus After Block Digestion
Monitoring station identifiers (1)

EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.

Other records on this page

Named boat-access points from the USGS National Boat Ramps inventory