The attack on the wood train was a decoy.

A group of warriors — typically estimated at between ten and twenty men — had been positioned to lure a relief force out of the fort and over the ridge, where a much larger body of warriors waited in concealment.

The decoy force showed themselves, drew fire, retreated, and drew Fetterman’s column into the pursuit.

The warriors ran slowly enough to keep the soldiers following, fast enough to maintain distance, drawing them steadily toward the ambush site.

When Fetterman’s command crossed Lodge Trail Ridge and began to descend into the valley beyond, they were surrounded on multiple sides by a force variously estimated at between 1,500 and 2,000 warriors.