 Montgomery County's North Country area went to Herkimer County on that county's formation in 1791, but western Franklin and eastern St. Lawrence were returned to Montgomery in 1797.In 1798 Lewis, Jefferson, and western St. Lawrence became part of the newly formed Oneida County from Herkimer in 1798, leaving only central St. Lawrence County as part of Herkimer.In 1801 the future St. Lawrence and Franklin counties which were portions of Montgomery, Herkimer, and Oneida were transferred to Clinton County; the next year in 1802 St. Lawrence was formed as a county.