Marais Rocheux was a vast terrain of woodland dotted with springs situated near the center of the River Valley of the New York state. During the Seven Years' War, it was the site of multiple encampments made by the Colonial Assassins, who operated against the British.
On 10 August 1757, Templar ally Shay Cormac sailed to Marais Rocheux to meet with the Templar Jack Weeks, where the latter informed Shay that Colonel George Monro had surrendered and the Abenaki, led by the Assassin Kesegowaase, planned to ambush them. Due to William Johnson and his reinforcements' absence, Shay decided to find Monro, so he could protect the colonel and his men himself. and escort the colonel and his men through Marais Rocheux to safety by eliminating the stalkers.
Fending off multiple attacks, they sighted Kesegowaase and his allies on a cliff, planning another ambush. After dispatching his snipers, Shay returned to Monro and escorted them to the Morrigan, narrowly escaping Marais Rocheux while being pursued by Kesegowaase.
- Marais Rocheux is French for "rocky swamp".