Niangua River

Bennett Spring is the reason most people fish the Niangua, and it's worth being honest about what that means: this is one of Missouri's four daily-stocked trout parks, and on the March 1 opening morning you'll share the spring branch with a thousand-plus anglers standing elbow to elbow for the horn. The spring itself is the draw — it pushes roughly 100 million gallons a day of cold, clear water out of the Ozark aquifer (the USGS spring-branch gauge runs a steady ~110–200 CFS year-round, barely flinching in a drought), and the state hatchery on the branch stocks rainbows into it every night the park is open. That constant cold water and constant fish make it a genuinely good place to teach someone to fly fish, dial in a scud-and-midge rig, or just catch a lot of stocked rainbows in the 10–13" range.

The more interesting fly water is below the park. The spring branch runs a short distance and dumps into the Niangua River, and MDC manages the next 11.5 miles — from the Bennett Spring branch confluence down to Prosperine Access — as a White Ribbon Trout Area with both stocked rainbows and, better, holdover and stocked brown trout. Browns run mostly 12–15" with a handful past 18", and the river changes character fast: the riffles right at the confluence wade well, but a lot of the Niangua downstream is deeper, boulder-strewn, and more than a wading angler wants to cross — this is float-and-wade water where you drift between the good runs. Below and mixed through the trout zone the Niangua is a strong smallmouth and goggle-eye stream, so a summer float can be a two-species day.

One honest caveat about the live data: the only streaming gauge on this page is the Bennett Spring branch gauge (USGS 06923500), which reads the spring's near-constant outflow — exactly the reach anglers fish in the park, but not the Niangua mainstem. The trout reach below the confluence has no live gauge of its own (the old mainstem stations are metadata-only), so judge the river visually after Ozark thunderstorms, when it blows out and goes chocolate fast, and watch temperature in drought summers when the lower reaches run low and warm enough to stress trout.