You did pretty well only trapping three areas and catching one your first year out. You can put a trap on a fisher travel route and not have one come through in 30 days. How close together were your three areas? How far apart were your sets? They have a large home range, especially the males. Your methods sound pretty good I think you just didn't have many fisher travel by your sets. I caught three, two males and a female. I started on the 13th. I had traps in five areas,(forty + mile round trip checks) eight traps total and I pulled three sets the day before the snow 'cause I didn't have time to walk in every day to check. I had a male fisher go by one of my set and not even give it a glance. That happens. If he would have come through again before the end of season I think I would have caught him, but he didn't. I tried 160 cubbies on the ground for a couple of years, my first fisher was in a ground cubby. I also had non target catches that ended my use of cubbies with square traps and cost me a permit. I have also tried them with foot traps and got nothing to show for it. They are fun to make though. My suggestions for next year will be after you answer my questions.
Dan