Where is Cottonwood Lake?

Cottonwood Lake is a lake in Sully County, South Dakota. Its water-quality measurements are published by SD DANR and shown on this page as reported.

Are there boat ramps on Cottonwood Lake?

Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Cottonwood Public Water Access. Public access is listed as yes.

Can I fish at Cottonwood Lake?

Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by South Dakota's fish and wildlife agency, so check its current regulations before you go.

Cottonwood Lake

Sully County, South Dakota462 acresView map Directions

No nutrient or algae sampling on record from SD DANR for this lake.

Area

462 acres

Surface area

Shoreline

4.8 mi

Measured length

Impaired · Mercury
Public access
Limited data

See the measurements Directions Where to stay

Cottonwood Lake in Sully County, South Dakota has water-quality measurements published by SD DANR, shown here as reported. Surface area: 462 acres.

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Cottonwood Lake is a 462-acre lake in Sully County, South Dakota. Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, SD DANR. Methodology: how these readings are compared.

What Cottonwood Lake 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. Cottonwood Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.

Whether Cottonwood Lake is safe to swim in today is a call for the South Dakota Department of Agriculture and Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Cottonwood Lake

These are the measurements SD DANR publishes for Cottonwood Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

No clarity data.

Ask about Cottonwood Lake

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

Lake Details

Surface area

462 acres

Shoreline

4.8 mi

Public access

Yes

Listed by SD DANR

No bathymetric survey has been published for Cottonwood Lake, so its depth is not documented here.

Recreation & Access

Boat Landings

Yes

Public Access

Cottonwood Public Water AccessPublic

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

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Stays near Cottonwood Lake

Compare lakeside cabins, hotels, and vacation rentals near Cottonwood Lake in Sully County, South Dakota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Cottonwood Lake

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Fishing Cottonwood Lake

→ Cottonwood Lake fishing regulations (limits, seasons, special rules)

EPA Impairment Status

Cottonwood Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).

Causes of impairment

Mercury

Designated uses not supporting: Aquatic life.

A Total Maximum Daily Load (TMDL) plan has been approved.

Source: EPA ATTAINS assessment unit SD-MI-L-COTTONWOOD_01 · Official waterbody report

Nearby Lakes in Sully County

Stone Lake8.2 miView →Durrstein Lake10.8 miView →Post Lake14.5 miView →Sully Lake15.9 miView →Walker Lake19 miView →Warnes Slough—View →

Frequently asked questions about Cottonwood Lake

Where is Cottonwood Lake?: Cottonwood Lake is a lake in Sully County, South Dakota. Its water-quality measurements are published by SD DANR and shown on this page as reported.
What is the water quality of Cottonwood Lake?: Cottonwood Lake in Sully County, South Dakota has water-quality measurements published by SD DANR, shown here as reported. Surface area: 462 acres.
Is Cottonwood Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Cottonwood Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Are there boat ramps on Cottonwood Lake?: Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Cottonwood Public Water Access. Public access is listed as yes.
Can I fish at Cottonwood Lake?: Cottonwood Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by South Dakota's fish and wildlife agency, so check its current regulations before you go.