A whole lot of trappers got butchered by the Indians and it was not usually a quick death as the Indians liked to cripple the white man then let the women and children torture them. A lot of them died and a whole lot more just "went under" or didn't show up at camp and were never accounted for. In my opinion, the stealth of not leaving tracks and sign had a lot more to do with being discovered.

This depended on where they were trapping of course as some areas had more friendly Indians than others. The Blackfeet were notorious for killing trappers on sight. But most of the bands were more than happy to steal traps and horses, and anything else useful, whenever the occasion arose. The trappers usually kept hiding during the day and set traps after dark, then pulled them before daylight. It was treacherous business not for the soft hearted.