Cowlitz River At Castle Rock flow report
As of July 13, 2026, Cowlitz River At Castle Rock is flowing at 2,830 cfs with a gage height of 33.23 ft. Source: USGS gauge #14243000, refreshed throughout the day.
Historical Data
Cowlitz River At Castle Rock at a glance
How Cowlitz River At Castle Rock is running right now, where it sits on the map, and the key gauge stats.
Cowlitz River At Castle Rock is flowing at 2,830 cfs, with the water sitting 33.23 ft at the gage.
This is USGS gauge #14243000 in Washington. Over the past 10 days the average has been 2,932 cfs, peaking at 3,090 cfs.
Over the next 5 days, Cowlitz River At Castle Rock is expected to hold near today's 2830 cfs, toward roughly 2774 cfs by 2026-07-18 (likely range 1800-4276 cfs) -- running well below the seasonal normal.
For real-time updates and historical context, see the realtime view or the historical comparison. Browse other gauges in the Washington flow report.
Streamflow Forecast
Powered by PULSE — Snoflo’s Predictive Unified Learning & Simulation Engine, which learns from how this river has answered every past storm, snowmelt, and dry spell to forecast where it’s headed with a precision generic models can’t match.
How does this compare to past years?
Year-over-year overlay, annual peak discharge, the full distribution of daily flows on record, and the gauge's rating curve.
Weather Forecast
Next 5 days, hour by hour
Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.
5-day forecast table
Every 3 hours, broken out across temperature, snow, rain, humidity, and wind.
| Time | Condition | Temp (°F) | Snow (in) | Rain (in) | Humidity (%) | Wind (mps) | Wind dir |
|---|---|---|---|---|---|---|---|
| Loading detailed forecast… | |||||||
15-day forecast
Daily temperatures, snow, and rain projected over the next two weeks.
Cowlitz River At Castle Rock
The gauge is located on the Cowlitz River, which receives water from various tributaries, including the Toutle River. The river is affected by several dams, including the Mayfield Dam and the Mossyrock Dam. The flow of the river is influenced by seasonal trends, with higher flows in the winter and lower flows in the summer. Interesting facts about the hydrology of the river include the presence of steelhead and salmon, which spawn in the river, and the fact that the river was historically used for logging and transportation.
Nearby streamflow levels
Cross-check Cowlitz River At Castle Rock's discharge against nearby gauges to spot whether the change here is local or regional.
| Gauge | Streamflow |
|---|---|
| Cowlitz River At Castle Rock | 2,830 cfs |
| Toutle River At Tower Road Near Silver Lake | 438 cfs |
| South Fork Toutle River At Toutle | 868 cfs |
| South Fork Chehalis River Near Wildwood | 56 cfs |
| Columbia River @ Beaver Army Terminal Nr Quincy | 81,000 cfs |
| Nf Toutle River Below Srs Near Kid Valley | 131 cfs |
Nearby snowpack data
Snowpack at SNOTEL stations near Cowlitz River At Castle Rock. Spring snowmelt is the dominant driver of streamflow in mountain basins -- a deep snowpack upstream means more runoff later in the season.
| SNOTEL station | Snowpack |
|---|---|
| Kelso-Longview Airport | 0 in |
| Nohrsc Sheep Canyon | 0 in |
| Sheep Canyon | 0 in |
| Spirit Lake Tunnel Outlet On S Coldwater Crk | — |
| Spirit Lake | 0 in |
| Swift Creek | 0 in |
Plan a trip
Reservoirs, boat launches, river runs, and fishing spots within driving distance of Cowlitz River At Castle Rock.
Nearby reservoirs
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Boat launches
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River runs
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River levels & flood safety
- Read the level before you go
- A river that's runnable at one flow can be deadly at another. Check current discharge and gage height — like the values shown above — against the flood-stage thresholds, and remember levels can spike fast after rain or a dam release.
- Respect cold water
- Snowmelt rivers run cold even in summer. Sudden immersion triggers cold-water shock and saps strength within minutes. Wear a PFD, dress for the water temperature (not the air), and never wade or paddle alone.
- Watch for swiftwater hazards
- Strainers (downed trees), undercut rocks, and low-head dams are the deadliest features on moving water. High, fast, muddy water hides them. If in doubt, scout from shore and portage.
- Mind flash floods & releases
- Narrow canyons can flood from a storm miles upstream, and dam-controlled reaches can rise without warning. Know the forecast, the release schedule, and your exit before you launch.
Track Cowlitz River At Castle Rock in the Snoflo app
Save this gauge as a favorite, set push alerts when streamflow crosses a threshold (e.g. "alert me when Cowlitz River At Castle Rock crosses 5,000 cfs"), and Snoflo's iOS app will push the moment USGS reports the crossing.
About Cowlitz River At Castle Rock
Where does the streamflow data for Cowlitz River At Castle Rock come from?
Discharge, gage height, and water temperature come directly from the USGS streamflow gauge 14243000. Snoflo refreshes the time series throughout the day. Forecasts come from the NOAA / yr.no feed Snoflo's iOS app uses.
How often is the report updated?
USGS gauges report continuously (typically every 15 minutes). Snoflo pulls fresh values throughout the day — look for the "as of" timestamp on the streamflow hero card.
What's the difference between discharge and gage height?
Discharge (cubic feet per second, or cfs) is the volume of water flowing past the gauge each second. Gage height is how high the water sits at the gauge (feet). They're related by a rating curve specific to each gauge — higher water means more flow, but the exact ratio depends on channel shape.
How is "percent of median" calculated?
Today's discharge is compared to the historical median discharge on this calendar day across the gauge's full record. 100% = right on median; 200% = a very high year; 30% = a drought-level low.
What are flood stages, and is this river safe right now?
Flood stages are NWS-defined gage-height thresholds — Action, Minor, Moderate, Major — marking when nearby roads or floodplains start to be affected. "Safe" depends on your activity and skill: a level that's a fun paddle for an expert can be lethal for a wader. Always check the current level against the thresholds above and the safety links, and when in doubt, stay off the water.
Can I get alerts when Cowlitz River At Castle Rock rises?
Yes — flow alerts are managed in the Snoflo iOS app. Favorite this gauge, set a streamflow threshold (e.g. "alert me when discharge crosses 5,000 cfs"), and you'll get a push the moment USGS reports the crossing.
Access the free Cowlitz River At Castle Rock report
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