Even modern steel claptraps are pretty gnarly, and their humaneness is debatable. I can only imagine that in the 1600's and 1700's the traps were even more gruesome, especially before there were strict laws governing hunting practices.
Did any fur traders express distaste or even remorse about what happened to pelt animals? When were the first attempts made to develop humane mechanisms for trapping?
Basically two types of traps were used before steel traps - snares and deadfalls. Snares were primarily used for small animals, and deadfall traps were used for everything, from martins and rabbits up to grizzlies. In the Nuxalk Language, there are over a dozen different words describing trapping and deadfalling, and it appears that (based on linguistic evidence alone), this was a common means of hunting all animals. Definitely better than going one on one.
As to the humaneness - snaring is what it is, strangulation, but deadfalls are much closer to the traps of today in that they were designed to kill immediately, not just hold. Nobody wants to have to personally kill a grizzly that is a few feet away being held there by something that might not work. These traps were truly huge, made with large trees and a large number of large rocks piled on top (though of course smaller traps for smaller animals). To see some deadfall trapping of small animals, you can check out https://www.youtube.com/watch?v=OusYaNWBy08 - happy people, a year in the taiga, and there's some showing of smaller deadfall traps for fur.