Mahnomen, Alstead & Arco Lake

How big is Mahnomen, Alstead & Arco Lake?

How deep is Mahnomen, Alstead & Arco Lake?

What kind of fish can you catch in Mahnomen, Alstead & Arco Lake?

Are there places to eat and drink near Mahnomen, Alstead & Arco Lake?

What are the fishing regulations for Mahnomen, Alstead & Arco Lake?

There are specific fishing regulations Mahnomen, Alstead & Arco Lake that you need to know. For complete fishing regulations visit the Minnesota Department of Natural Resources. To report a violation call (800) 652-9093. Need a Minnesota fishing license?

What aquatic invasive species are found in Mahnomen, Alstead & Arco Lake?

Mahnomen Mine Pit Lake is a complex of former open pit iron mines located north of Ironton that has filled with water. The Mahnomen complex includes (from east to west) the Mahnomen No. 1, Louise, Mahnomen No. 2 and 3, Arco, and Alstead mines. Mahnomen Mine Pit Lake is the largest mine pit lake in the Cuyuna Range at 270 acres and the deepest at over 500 ft in Mahnomen No 1. The water is very clear with visibility to a depth of nearly 30 ft. A concrete boat launch is located on the west end of Pennington Mine. A channel on the northeast end of Pennington connects to Mahnomen Mine. Mahnomen is within the Cuyuna Country State Recreation Area.

Mahnomen is a designated stream trout lake. Designated stream trout lakes have additional angling regulations. Be sure to consult the current Minnesota Fishing Regulations book for regulations, seasons, and possession limits before fishing designated trout waters.

A survey of the fish community and aquatic habitat in Mahnomen Mine Pit Lake was conducted in 2010. The fish community was assessed with 13 gill net and 11 trap net sets. The total catch in the gill nets was fairly low at 14.2 fish per set, but this was comparable to other Cuyuna mine pit lakes where average gill net catches have ranged from 2 to 63 total fish in recent surveys (median 9.7). Yellow perch were the most common fish in the gill nets with a catch of 8.0 fish per net. The northern pike gill net catch was only 1.7 per set, but they comprised about one-half of the gill net catch biomass with a mean weight of 5 lbs per fish. Northern pike captured in the gill nets ranged in length from 11 to 41 inches with an average length of 26 inches. Smallmouth bass were the third most common fish in the gill nets and were fairly large with a mean length of nearly 15 inches; the largest was 18.9 inches long. A few large walleyes were captured in the gill nets.

Bluegills were the most common fish in the trap nets with average catch of 13 per set. Most bluegills were from 3 to 7 inches long. Black crappies were the second most abundant species in the trap nets at 2 per net and about 60% were greater than 8 inches, while in the gill nets most black crappies were around 10 to 13 inches long. Catch of other species was fewer than 2 fish per trap net.

Temperature and oxygen conditions suitable for trout occurred from a depth of about 20 ft down to about 85 ft. The water was extremely clear with visibility over 25 ft. The water chemistry had low phosphorus and chlorophyll, but had fairly high ionic strength and alkalinity.

Near shore substrates were primarily sand and gravel. The aquatic vegetation was fairly diverse compared to other nearby mine pit lakes; 23 species or species groups were identified in the August survey. Submerged trees which extend nearly to the surface are common in areas of medium depth - about 10 to 30 ft deep.

Stocking plans and stocking histories for the Mahnomen Mine Pit complex are all stored under the records for Pennington Mine Pit Lake (18-0439-00). See the Pennington Mine 2010 survey report for more stocking and survey information.

What is the average air temp for Mahnomen, Alstead & Arco Lake?