Weasels are everywhere in the 48 states. They are not often seen, even after they have snuck in and killed a number of your birds in a single night.Thanks for the advice and info, folks. We've decided to go with 2x4 welded wire, which we'll fold over the outer edge of the walls and staple along the top of the walls. We have wire to attach overlapping panels.
We're in a suburban area so don't think weasels are around here. Snow is uncommon here but we also have a tarp covering most of the run (attached to an old carport frame, not the run walls). We'll keep in mind electric options if we continue to have problems.
Thanks again!