R.O.U.S.? Hmmm, I had just passed through the dreaded fire swamp...
The first sighting was probably a fisher, since it's size was in the 10 to 15 lb. estimate. The second may have been a mate, or a different species. The first seemed to have some white/light color on its body. While the second I spotted from above, so I never saw anything but his very thick and black fur.
I imagine they're territorial, so I assumed it was a mate. It was probably 2/3 the size of the first one, but I was also further away. Some 30 feet as opposed to 10 feet.
If only them thar weasels were posers we'd know for sure.