Lake Irving is a natural lake on the Mississippi River system located within the city of Bemidji in southern Beltrami County. There is a considerable amount of lakeshore development due to the immediacy of the downtown area and numerous lake homes. There is a public water access located on the north end of the lake adjacent to the city's wastewater treatment facility. The lake is easily accessible from Lake Bemidji via a short trip up the Mississippi River, although boaters should navigate with caution in the area of the river channel and outlet of Lake Irving due to old railroad pilings that are still present. The lake's direct connectivity with Lake Bemidji and the river system is beneficial to fish populations due to seasonal movements of species such as walleye and northern pike. Lake Irving has a maximum depth of 19 feet and is known as a good early season lake in both the open and hard-water fishing seasons.
Lake Irving's walleye population is sustained primarily through natural reproduction and migration which both occur throughout the Mississippi Headwaters system. The 2012 population assessment documented a healthy walleye population in Lake Irving (similar to Lake Bemidji) with a catch rate of 14.56 fish/gill net, which is well above the statewide normal range for class 39 lakes. Average length and weight of the 2012 walleye sample was 13.8 inches and 0.95 pounds, with a good proportion of "eater" size walleye from 12 to 16 inches in length. An abundance of young walleye from age-1 through age-3 indicates successful reproduction and good potential for walleye fishing in the near term.
Black crappie and bluegill inhabit Lake Irving in low numbers with some quality-size individuals present in the population. The black crappie catch rate of 1.0 fish/trap net is just within the normal range for lake class. Black crappie up to 14.2 inches in length were captured in 2012, with a good representation of younger fish in the sample indicating recent reproduction. Bluegill, which were sampled in very low numbers in previous assessments, appear to be expanding their population in Lake Irving. The 2012 catch rate of 12.38 fish/trap net is up from 0.67 fish/trap net in 2001 and is now within the normal range for lake class. Bluegill up to 9.5 inches in length were captured in 2012.
Northern pike were sampled at 6.44 fish/gill net, which is within the normal range for lake class. Average length and weight of the northern pike sample was 20.8 inches and 1.9 pounds. There has been a decline in the proportion of northern pike greater than 30 inches in length, which is occurring on many lakes in the area. Anglers can help reverse this trend by releasing northern pike over 24 inches in length and keeping smaller pike for table fare.
Other species present in the 2012 assessment included pumpkinseed, bullhead species, redhorse species, white sucker, rock bass, yellow perch and largemouth bass.