The markings could be a result of the browns being frequently snagged due to the large amount of nymph fishing done on the Provo. I also do most of my winter and fall fishing on the Provo, while devoting the summer to the Green. Perhaps this could have something to do with the coloration differences. Thanks.

A. I called Dr. Robert Behnke at Colorado State U. to see if he had any experience with the trout from the Provo and Green. He didn't, specifically, but suggested that color variations can be influenced by various factors including both stocking history and heredity. Brown trout stocks originated in both Germany and Scotland, but you would have to study the stocking and rearing records of the strains planted in your two rivers to see of the color differences might be traced to different stocks. Environmental factors can also influence color variations; the old "nature vs nurture" argument. Hatchery folks will tell you that diet can affect color; also, hatchery fish tend to be lighter in color than wild fish. That's about the best I can come up with on the color variations you've observed.

As to the scarlike markings, neither Bob nor I think it could have anything to do with nymph fishing. It is highly unlikely that accidental snagging by nymphs could be as extensive as you indicate. A more likely source would be scarring by rocks tumbled downstream during high flow periods, and even this is unusual.