 On June 5 , just hours before Sullivan 's arrival , Thompson sent 600 troops under the command of Colonel Arthur St. Clair toward Trois @-@ Rivières with the goal of surprising and beating back the small British force believed to be there . Sullivan , on his arrival at Sorel , immediately dispatched Thompson with an additional 1 @,@ 600 men to follow . These forces caught up with St. Clair at Nicolet , where defenses against troop movements on the river were erected the next day . On the night of June 7 , Thompson , St. Clair , and about 2 @,@ 000 men crossed the river , landing at Pointe du Lac , a few miles above Trois @-@ Rivières . 
