🐟 Bighorn River, Montana Renowned for its beautiful scenery and trout abundance, the Bighorn River is regarded as one of the most beautiful fishing streams not just in Montana but the entire country. Though localized to the first 13 miles, the river offers fly fishing enthusiasts an opportunity to fish for the whole year. Yes, even including in the middle of winter. This stretch has a population of about 3000-5000 fish per mile, with a considerable portion of the fish being over fourteen inches. The river mostly harbors brown trout, but prized rainbows are also abundant. The best fishing period is during the summer between July and September, but anglers are present even during the cold, dead of winter.