They are stocked trout... They have a trout rodeo every year and they are left overs from the rodeo... They stock 1000 lbs and a lot are never caught... They are really finicky and they see a lot of pressure... The brown I hooked wasn't stocked this year he was to big and I think it's been atleast 4 years since they stocked browns so it might have been from then... Pretty neat tho this year they put in browns brookies rainbows and golden trout... I saw a few gold ones last Sunday but those suckers are super finicky... The river I'm fishing does have quite a few natives in it also... That brown could have been one of those too which I'll probably never know lol... I've caught browns up to 19" (natives from that river) and rainbows up to 25"... I've caught a few bigger browns but none over 19" there