How do I read a USGS gauge to know if a river is fishable?
Don't read raw cubic-feet-per-second numbers in isolation. The same flow number can mean "blown out" on one river and "low and clear" on another. Instead, compare current flow to the river's historical distribution: a flow at the 30th–70th percentile is typically ideal for steelhead, above the 90th percentile is high and stained, below the 10th percentile is low and clear.
Steelhead Addiction maps each USGS gauge reading onto the river's own log-normal flow distribution and shows the result as a percentile-zoned gauge bar with six color-coded bands (Very Low, Low, Normal, High, Very High, Flood). The optimal-flow zone is overlaid as a dashed green band. This lets anglers compare conditions across rivers ("Conneaut at 320 CFS is in the sweet spot, Cuyahoga at 320 CFS is bottom-25%") without memorizing per-river thresholds. Each river page also includes a 72-hour sparkline so you can see the trend (rising / falling / stable) at a glance.
