After US 9 passes Ausable Marsh Wildlife Management Area and NY 442 comes in from the east at the small hamlet of Peru, US 9 heads down to the shore of the lake itself, which it will stay close to all the way into Plattsburgh as Lakes to Locks Passage. On clear days it is possible to see Burlington across the water. Ahead lies Valcour Island. In the narrow, rocky strait between it and the shore, Benedict Arnold's hastily built fleet held off the British on October 11, 1776 in the Battle of Valcour Island in what is considered the first battle in U.S. naval history. More recent military history is apparent shortly thereafter when US 9 passes now-closed Plattsburgh Air Force Base, a pillar of the regional economy Plattsburgh has struggled to replace.