Mahnomen, Alstead & Arco Lake

Crow Wing County, Minnesota - DNR stocking history, depth and survey data

Minnesota · Minnesota Department of Natural Resources (DNR) · DOW 18044000

Mahnomen, Alstead & Arco Lake has no DNR stocking rows in LakeFinder; this page carries its DNR depth, access and survey data.

• Mahnomen, Alstead & Arco Lake shows no stocking records in Minnesota DNR LakeFinder as of September 2, 2026.
• Maximum depth 525 ft; surface area 272 acres, 53 littoral acres, 8.1 miles of shoreline, per the DNR lake survey.
• Average water clarity (Secchi depth) 32.3 ft.
• Fish species DNR lists here: black bullhead, black crappie, bluegill, burbot, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rainbow trout, rock bass, smallmouth bass, tullibee (cisco), and 4 more.
• 1 public access on the DNR list.
• Most recent DNR fish survey: July 5, 2022 (standard survey).
• Crow Wing County, nearest town Armour Number Two Mine; DNR lake number (DOW) 18044000.

Depth map

Bathymetric contours from the Minnesota DNR lake survey; depths in feet. Simplified for the web; not for navigation.

Public accesses

DNR fish survey, 2022

Catch per net (CPUE) is the DNR survey's count per gill net or trap net set; higher means more of that species were sampled, not a fishing forecast. Top species per gear shown; where we have no verified common name for a DNR code, the code itself is shown.

Mahnomen Lake is a complex of former open pit iron ore mines located in the Cuyuna Country State Recreation Area. The Mahnomen complex includes (from east to west) the Mahnomen No. 1, Louise, Mahnomen No. 2 and 3, Arco, and Alstead mines. Temperature and oxygen conditions suitable for trout occurred from a depth of about 20' down to around 70'. Rainbow Trout were first stocked in 1982 and are stocked annual as yearlings (15,000/year) into the Mahnomen complex and connected Pennington. Rainbow Trout provide for a popular fishery, especially early in the season. Rainbow Trout were sampled at 4.6/gill net which was the highest catch to date. Average length was 10.9". Lake Trout were first stocked in Mahnomen in 2019 and are stocked biennially as yearlings (1,670/year). No Lake Trout were sampled in this survey, although there are reports of anglers catching a few. Tullibee (Cisco) were also stocked in 2019 to provide forage for the Lake Trout. Tullibee (Cisco) were sampled in low numbers, when compared to similar lakes, at 0.6/gill net. Northern Pike were sampled in low numbers at 1.0/gill net. Average length was 21.6", with 8% in the protected 22"-26" slot, and 50% at least 26.0" in length. Northern Pike up to 31.7" were sampled. Largemouth Bass were sampled in average numbers, when compared to similar lakes, at 1.3/gill net. Average length was 12.0", with fish up to 20.5" sampled. Smallmouth Bass were also sampled in average numbers at 0.3/gill net. Average length was 17.2". 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. Zebra mussels are present in Mahnomen Lake. Before and after launching lake users are required to inspect and remove any aquatic plants and animals from their watercraft and trailers as well as pull the plug and drain all water from the watercraft, including bilges, livewells and baitwells.

Minnesota DNR survey narrative, July 5, 2022.

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