Loggers moved around a lot way back in the day when there were lots of little outfits and I believe the term "gypo" came from Gypsy, although some people may think it came from some of the rather nefarious actions of some of them wherein guys didn't get paid for their work and the like, so they were gyped by a gypo.
As to unions, the IWA had all the big companies during the '60's, '70's and into the '80's for the most part and it was a pretty good set-up. Cheap room and board in camp, travel time, 2/3rds if you drove truck or operated equipment etc. etc.
Naturally there were always guys who would screw around and abuse the basic system or whatever and in particular the fallers at the BCFP Renfrew logging division were really bad at making puppies and had to be treated with kid gloves in order to get anything out of most of them. Worst bunch of useless prima donnas ever, with a few exceptions of course.
The worst place for watching puppy makers in a union was when I worked in the pulp mill at Gold River. I was fresh out of the military and went into a unionized environment where there were lots of ridiculous duplications of effort or requirement to have some trade present when something was done that might require them ad nauseum which was difficult to relate to after three years of yes sir no sir and strict regulations and all that.
Lots of good and bad regarding unions for sure, but generally for loggers the IWA (now Steelworkers I think) was not a bad deal.
Your mileage may vary.
Take care.