Explore 8,800+ river gages
Click a state to see its rivers and gages — or search below to look across all of them.
How to read this map
Each state is shaded by the mean of its gages' most recent daily-mean flow, on a log10 scale — one step of colour is a 10× difference, because rivers span orders of magnitude. Orange is drier than the national spread, blue is wetter, and grey means no gage in that state has reported in the last 7 days. States with no gages in the registry stay flat and unclickable.
Most gages:
What does "Nearest me" use?
Straight-line (great-circle) distance from your device's approximate position to each gage's station coordinates — not driving distance, and not necessarily the same watershed. The calculation happens in your browser; your position is not sent to us.
What's a water year?
Oct 1 – Sep 30, named for the year it ends in. Hydrology uses it so one snowpack-to-melt cycle stays inside a single year. "Years since first record" on each card is calendar span, not water years.
Showing the first 300 of 419 matches — refine your search.
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