• In Idaho, I was told that the state has the most miles of river in the USA. Research revealed that Idaho has 107,651 miles of river and is state #10 for the most miles. • A quick google search claims that Nebraska has the most miles of river. I found it wildly disseminate across the internet that Nebraska has the most miles of river. Yet, Nebraska has only 79,056 miles of river making it state #17. • Alaska with over 365,000 miles of river has the most miles of river in the USA. The milage above was sourced from River.gov. Other sites have conflicting statements about the river mileage. My advice is to just go explore them all!