Captain Rogers was sent on a reconnaissance mission from Fort Edward northwards toward Fort Carillon on March 10, 1758. Lieutenant Colonel William Haviland, the fort's commander, had originally planned on 400 men taking part but reduced the number to 180, even though he had reason to believe the French knew of the expedition. The French had captured a man from an earlier expedition by Israel Putnam's Connecticut rangers and it was suspected that he had informed his captors of the British plans. Putnam's reconnaissance revealed that there were an estimated 600 Indians encamped near Fort Carillon.