Geography
Deer Lake (MN DNR LakeFinder Details) is located in Itasca County, about 12 miles north of Grand Rapids and about 8 miles NE of Deer River. The lake covers 4,097 acres and is roughly 5 miles long and 1.5 miles wide. There are 20.7 miles of shoreline (25.6 if islands are counted). The lake has no inlets and only one outlet into the Deer River. Its water comes from rainfall and numerous surface and underground springs. Deer Lake is considered “oligotrophic” indicating very clear water with low nutrient levels. Deer Lake’s depth ranges up to 121 feet. There are many reefs and rockpiles, some rising suddenly in mid-lake. The lake has 920 acres of “littoral area” (where the depth is less that 15 feet deep).
Development
In a 2005 survey, the state counted 359 private “improved parcels” on Deer Lake (homes or cabins), indicating a relatively high level of shoreline development. An additional 141 non-improved parcels were mostly in common ownership with the improved, but recent development since 2005 has seen many more homes and cabins built around the lake. The State of Minnesota owns just 12 parcels, the majority of which are islands.
Fishing
The lake’s rocky littoral area is great for fishing, but presents real concerns for the safe boater. Many anglers come to catch trophy muskies, but small-mouth & large-mouth bass, walleyed pike, northern pike and a wide assortment of panfish are also present. Very clear water presents a challenge for daytime fishing.
“The Lake of Changing Colors”
Dubbed by locals as the “Lake of the Changing Colors,” Deer Lake’s crystal-clear water contains minerals that changes it’s water to a brilliant blue-green turquoise color on a bright summer day. This color, along with it’s many islands and miles of scenic shoreline, makes Deer Lake one of northern Minnesota’s treasures.
The changing colors are the result of “marling,” which occurs in lakes with a high calcium concentrate. Changes in water chemistry (principally temperature and PH) can trigger the calcium carbonate to crystalize. These microscopic crystals are known as “marl” and become suspended in the water, slowly sinking. The bright sunshine during the summer brings about the beautiful turquoise colors. Observation of the changing colors depends on such aspects as angle of view, water turbulence, and time of day. The precipitation of the calcium is thought to improve water quality due to the decrease of nutrients through the crystallization process. However, the calcium in the water also helps zebra mussels to form their shells.