Put before daybreak Sir Henry transported 2,000 of his force from Verplanck's Point to the wholly unprotected west shore, leaving 1,00(1 behind to keep up the appearance of a meditated movement on Putnam. Then, with his main body, he made the circuit of the Dunderberg, marched without experiencing the least detention through those mountain passes which Washington's board of generals in May had reported were so exceedingly difficult that they would never be attempted, easily overcame the small corps sent to check him, and, in two divisions of a thousand men each, fell upon Forts Clinton and Montgomery from the rear. He stormed them with the bayonet, and though the forts were heroically defended, the Americans prolonging their resistance until twilight, the overpowering numbers of the British carried the day. The American killed, wounded, and missing were 250. The two commanders, with the remnants of the garrisons, escaped across the river. In the action Colonel Campbell, heading one of the attacking parties, was killed, and his command fell to Colonel Beverly Robinson, the Loyalist son-in-law of the third Frederick Philipse. Fort Independence, on the Westchester side above Peekskill, did not prove strong enough to prevent the passage of the warships belonging to the expedition. Two or three of these vessels ran by its batteries and co-operated with the land force. Governor Clinton was informed somewhat in advance of the coming of the enemy through the passes, and sent to Putnam for help, but his messenger never reached the doughty general. Irving says he turned traitor and deserted to the enemy. Putnam had been completely outmaneuvered. Although the crossing of a British force to the west side had been reported to him, he supposed this was only a detachment, and thought the main body was still at Verplanck's Point, and