Skip to main content
LakeQuality
Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water

Fremont County Lake Quality

Idaho, 18 lakes, measured by Idaho DEQ

There are 18 monitored lakes in Fremont County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. 2 of those lakes carry recent nutrient and algae readings. The county-level summary describes that subset, not every water body listed. Phosphorus and algae readings vary widely across Fremont County; the per-lake pages below carry the numbers.

The county's lakes lean shallow, which makes the readings sensitive to wind, sediment-resuspension, and any nutrient inputs from the watershed. The cleanest measured lake is Island Park Lake.

Loading map…

Where to stay near Fremont County

Top-rated places to stay near Fremont County

Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a trip to Fremont County?

Get lake water-quality updates plus the best cabin & lodging deals near Fremont County — straight to your inbox. No spam, unsubscribe anytime.

All Lakes in Fremont County

18 lakes · 2 ranked on readings, 16 without enough sampling2 lakes ranked on readings · 16 without enough sampling, hidden

#LakeClarityPhosphorusAlgaeTrophicAccess
1Island Park LakeFremont9.8 ft24 µg/L11.8 µg/LNo recent samples✓ Public
2Island Pk ReservoirFremont2.3 ft56 µg/L9.8 µg/LNo recent samplesNot recorded
Henry'S Lake @ Boat RampFremontNo recent samples11 µg/L1.5 µg/LNo recent samples✓ Public
Henrys LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samples✓ Public
Ashton ReservoirFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Horseshoe LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Robinson LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Beaver PondFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Fish PondFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Swan LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Silver LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Golden LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Sand Creek ReservoirFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Upper Arcadia ReservoirFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Lower Arcadia ReservoirFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Lemon LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Egin LakesFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
Quayles LakeFremontNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded

NR = no nutrient or algae reading on record. The measurements are published as the authority reports them. Where the data comes from.

Lake Match

Which lake suits how you actually use one?

Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of lakes that fit, with the water quality behind each one.

Take the quiz →

Browse every Idaho lake, or the full directory of lakes across all United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs..

Source: the Idaho Department of Environmental Quality. See data sources.