|Nearest Town: Ironton
Primary County: Crow Wing
|Survey Date: 07/12/2010|
Inventory Number: 18043900
|DNR||Concrete||West end of mine.|
|Did you know? Each year, the MinnAqua program teaches youth and families across Minnesota about aquatic biology, fishing, and conservation..|
|Species||Number of fish per net||
Average Fish Weight (lbs)
Normal Range (lbs)
|Black Crappie||Trap net||0.67||0.5 - 2.2||0.38||0.3 - 0.5|
|Bluegill||Trap net||54.67||7.7 - 43.4||0.09||0.1 - 0.2|
|Hybrid Sunfish||Trap net||0.33||N/A||0.35||N/A|
|Largemouth Bass||Trap net||1.00||0.4 - 1.5||0.05||0.2 - 0.7|
|Northern Pike||Trap net||0.67||N/A||1.37||N/A|
|Gill net||1.00||2.2 - 8.7||7.04||1.5 - 3.2|
|Pumpkinseed||Trap net||0.33||1.4 - 5.9||0.22||0.1 - 0.2|
|Rainbow Trout||Gill net||3.00||N/A||0.50||N/A|
|Rock Bass||Trap net||2.67||0.8 - 3.7||0.10||0.2 - 0.4|
|Yellow Perch||Trap net||2.33||0.4 - 2.3||0.12||0.1 - 0.2|
|Species||Number of fish caught in each category (inches)|
|For the record, the largest Longnose Gar taken in Minnesota weighed 16 lbs., 12 oz. and was caught: |
Statistics: 53" length, 16.5" girth
Fish Stocked by Species for the Last Ten Years
|1 - indicates fish purchased and stocked by private citizens and sporting groups.|
|2 - indicates fish purchased by the DNR for stocking.|
|Stocking Fish Sizes|
|Fry - Newly hatched fish that are ready to be stocked usually called "swim-ups". Walleye fry are 1/3 of an inch or around 8 mm.|
|Fingerling - Fingerlings are one to six months old and can range from a size of one to twelve inches depending on the species. Walleye fingerlings range from three to eight inches each fall.|
|Yearling - Yearling fish are at least one year old. A one-year-old fish can range from three to twenty inches depending on the species. Walleye yearlings average from six to twelve inches.|
|Adult - Adult fish are fish that have reached maturity. Depending on the species, maturity can be reached at two years of age. Walleye reach maturity between the ages of four and six years.|
Pennington Mine Pit Lake is a former open pit iron mine located north of Ironton that has filled with water. Together with the connected Mahnomen Mine Pit Lake this complex is the largest mine pit lake in the Cuyuna Range with a total surface area of 320 acres. The deepest water in Pennington is over 250 ft. 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. Pennington is within the Cuyuna Country State Recreation Area.
Pennington 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 Pennington Mine Pit Lake was conducted in 2010. The fish community was assessed with 3 gill net and 3 trap nets. The total catch in the gill nets was 4 fish per set, and this was low compared to other Cuyuna mine pit lakes where average gill net catches have ranged from 2 to 63 total fish in recent surveys (median of 9.7 fish per net). Only two species were captured in the gill nets: rainbow trout and northern pike. The rainbow trout (3 per gill net) were all age-1 fish from the spring 2010 stocking of 20,062 rainbow yearlings and ranged in length from 9 to 11 inches. With an average weight at capture of 0.5 lbs, the rainbow trout did show some growth after stocking. The April 5 stocking of 10,500 yearlings had an average weight of 0.3 lbs and the May 3 stocking of 9,562 yearlings had an average weight of 0.4 lbs at stocking. Two of the northern pike captured in the gill nets were 33 inches long, and the third was 28 inches long for an average weight of 7 lbs per fish.
Bluegills were the most common fish in the trap nets with average catch of 55 per set. Bluegills ranged from 3 to 6 inches long. Rock bass were the second most abundant species in the trap nets at 2.7 per net. The catch of other species was fewer than 2 fish per trap net.
Several other fish species were found in a concurrent survey of the connected Mahnomen Mine Pit Lake that were not found in Pennington. These species included: bowfin, burbot, smallmouth bass, walleye, white sucker, and yellow bullhead. All of these species could likely be found in Pennington.
Temperature and oxygen conditions suitable for trout occurred from a depth of about 16 ft down to about 42 ft. The water was extremely clear with visibility about 30 ft. The water chemistry had low phosphorus and chlorophyll, but had fairly high ionic strength and alkalinity.
Near shore substrates were primarily sand with some gravel and cobble. Submerged trees which extend nearly to the surface are common in areas of medium depth - about 10 to 30 ft deep.
Rainbow trout were first stocked into Pennington Mine Pit in 1982. Since the early 1990's usually about 20,000 spring yearling rainbow trout have been stocked annually. Starting in 2011 Pennington is scheduled to receive 15,000 rainbow trout yearlings annually. Some of the Pennington quota has been stocked into the connected Mahnomen Mine Pit (18-0440-00) in recent years. Trout stocked in the Mahnomen complex are recorded as being stocked into Pennington.
See the Mahnomen Mine Pit Lake (18-0440-00) 2010 survey report for more survey information on this complex of mine pit lakes.
|For more information on this lake, contact:||Lake maps can be obtained from:|
For general DNR Information, contact:
DNR Information Center
500 Lafayette Road
St. Paul, MN 55155-4040
TDD: (651) 296-6157 or (888) MINNDNR
Turn in Poachers (TIP):
Toll-free: (800) 652-9093