Some of the beaver ponds were stocked with fish that had were non-local.

The extreme difficulty is that a fish may shift from resident to anadromous and back again. We trapped a female going up and downstream. Then up. After that, she spent a year in the lake.

We marked about 1,000 or so CT rearing in freshwater. The marking showed that some smolted and some didn't. As juveniles, they pretty much looked the same.

The only consistent difference I could see between resident and sea-run was that one of the two (I forget which) had spots on the anal fin. I think it was in the resident zone where the spots showed up but even then it was not 100%.

To show the variation, we had one bio from Idaho that said this one fish, if it was in Idaho, would be a Westslope based on spotting. As I recall, we had both large and fine-spotted fish.