Why Riffle Exists
Stream intelligence that helps you catch fish.
You drive three hours to a river and it's blown out. You fish through a dead afternoon and find out the hatch happened two hours earlier. You check five websites trying to piece together flow data, weather, and hatch reports before deciding where to go this weekend.
That's the problem Riffle solves.
The Data Is Already There
USGS publishes near real-time flow and temperature from thousands of gauges. NOAA provides weather forecasts. SNOTEL tracks snowpack. All public, all free. But none of it is presented through a fly fishing lens.
A gauge reading of 1,240 CFS doesn't tell you if the river is fishable. A water temp of 54°F doesn't tell you what's hatching. Riffle connects the dots.
How It Works
Riffle interprets stream data the way an experienced angler would. 54°F means you're in the prime feeding window, mayflies are likely active, and a parachute Adams is a reasonable starting point.
Flow at 150% of the 10-year median means size up your nymphs, add weight, fish the slower edges, and think about streamers.
Hatch predictions use Growing Degree Days — the same science entomological researchers use — applied to actual USGS water temps. Instead of a generic chart that says "March through May," you get specific timing: BWOs on your home water are at 73% of their GDD threshold, emergence in roughly 12 days.
What It's Not
It's not a weather app with a fish icon. It's not a social media platform. There's no public feed, no public profiles, no spot burning. Friend connections are private. Your fishing data stays yours.
The trip journal auto-captures USGS conditions on every outing, building a personal database that correlates catches with verified stream data. Over time, the app surfaces patterns — what works on which river at what temperature and flow — and alerts you when those conditions come back.
700+ Rivers
Curated hatch charts, regulations, and fishing report sources for 700+ rivers, from the Madison to the Deschutes to the South Platte. The database grows every week. Beyond the curated list, any of the ~9,000 USGS gauge stations nationwide can be checked for current conditions.