Copco Lake is a lake in Siskiyou County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.

Are there boat ramps on Copco Lake?

Copco Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Copco Reservoir (Mallard Cove). Public access is listed as yes.

Can I fish at Copco Lake?

Copco 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 California's fish and wildlife agency, so check its current regulations before you go.

Copco Lake

Siskiyou County, California994 acresView map Directions

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

Area

994 acres

Surface area

Shoreline

13.3 mi

Measured length

Impaired · Biotoxins
Public access
Limited data

See the measurements Directions Where to stay

Copco Lake in Siskiyou County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 994 acres.

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Copco Lake is a 994-acre lake in Siskiyou County, California. Limited fish-species data available. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, your state environmental agency. Methodology: how these readings are compared.

What Copco Lake is good for

From access and monitoring records, not editorial picks.

Boat launch1 documented ramp

Swimming conditions

No reading

Bacteria advisory

Nutrient and algae readings are not a swimming clearance. Copco Lake is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury. Check local advisories before you swim.

Whether Copco Lake is safe to swim in today is a call for the California State Water Resources Control Board and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

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Water quality measurements for Copco Lake

These are the measurements SWRCB publishes for Copco 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 Copco Lake

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

Lake Details

Surface area

994 acres

Shoreline

13.3 mi

Public access

Yes

Listed by SWRCB

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

Recreation & Access

Boat Landings

Yes

Public Access

Copco Reservoir (Mallard Cove)Public

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 Copco Lake

Compare lakeside cabins, hotels, and vacation rentals near Copco Lake in Siskiyou County, California — 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 Copco Lake

Prices for Oct 16–18, 4 adults. Change dates on the map below.

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Fishing Copco Lake

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

EPA Impairment Status

Copco Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

BiotoxinsMercury

Designated uses not supporting: Fish consumption, Recreation, Other.

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

Source: EPA ATTAINS assessment unit CAL1053802120020720133912 · Official waterbody report

Nearby Lakes in Siskiyou County

Iron Gate Reservoir7.2 miView →Juanita Lake14.5 miView →Meiss Lake15 miView →Steamboat Lake—View →Bass Lake—View →Trout Lake—View →

Frequently asked questions about Copco Lake

Where is Copco Lake?: Copco Lake is a lake in Siskiyou County, California. Its water-quality measurements are published by SWRCB and shown on this page as reported.
What is the water quality of Copco Lake?: Copco Lake in Siskiyou County, California has water-quality measurements published by SWRCB, shown here as reported. Surface area: 994 acres.
Is Copco Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Copco Lake is listed impaired under Clean Water Act §303(d) (IR 5) for biotoxins, mercury. Check local advisories before you swim.
Are there boat ramps on Copco Lake?: Copco Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Copco Reservoir (Mallard Cove). Public access is listed as yes.
Can I fish at Copco Lake?: Copco 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 California's fish and wildlife agency, so check its current regulations before you go.