Local fishing information, including Fishing News, Fishing Reports and links to Fishing Guide Services » New York Lakes » Otsego Lake Login | Home Leatherstocking & Central Region Advice. Don't see your waterbody listed in the table? If there is no specific advice for a particular waterbody, follow the general advice, which is to eat up to four, half pound meals a month of fish. Apr 03, 2009 · Lake Notes: Otsego Lake is nine miles long and the source of the Susquehanna River. During the months of May and June there is good fishing for pickerel and bass. Late June, July and August provide great Largemouth bass fishing. In the Fall it is not uncommon to catch a 10lb lake trout or a 4lb smallmouth bass. Otsego Lake lies in the glacially overdeepened headwaters of the Susquehanna River in Otsego County, New York (42E40'N-70E00'W ) within the northern portions of the Appalachian Plateau. It is oriented, with its main axis north to south, in a glacially overdeepened valley at an elevation of between 364.2 and 364.5 m.