Except for the touristy town of Bigfork [1] at the northeastern edge, the east side of Flathead Lake [2] is even less developed than the west side [3]. Toward the southern end of the lake, cherry orchards are both a business and an attraction around Flathead Lake. Cherries are usually harvested beginning the third week of July.
The University of Montana [4] runs the Flathead Lake Biological Station (406/982-3301, www.umt.edu/flbs [5]) at Yellow Bay. Limnology, the study of the life of lakes, ponds, and streams, especially research on water quality and plankton, is a major focus here. Summer classes in freshwater biology and ecology are offered for credit and for audit.
If your interest is more casual, drop by the station. Students are often pleased to discuss their research, and there are newsletters and bulletin boards to browse.
Links:
[1] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/flathead-lake/bigfork
[2] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/flathead-lake
[3] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/flathead-lake/west-side-flathead-lake
[4] http://www.moon.com/destinations/montana/missoula-and-northwestern-montana/missoula/sights/university-montana
[5] http://www.umt.edu/flbs