Au Sable River at Grayling
Michigan · Paddling & whitewater
Measured at USGS 04136000 — AU SABLE RIVER NEAR RED OAK, MI · NWS forecast point RDOM4
Reading taken Jul 28, 11:45 PM UTC
Up — bigger, pushier water than average
At 1,030 CFS, this gauge is running 165% of normal for late July — above the 625 CFS median USGS has recorded for this date across 36 years of record (1909–2026). The stage is 2.5 ft below the NWS action stage of 6.0 ft.
Data-derived guidance from USGS and NWS published values — not official advice, and not a safety assessment.
Sponsor Au Sable River
Put your outfitter, guide service, cabin rental or shuttle in front of everyone checking this stretch before they drive out. One exclusive sponsor per river.
Cancel anytime · Questions?
Flood stages at Grayling
Official National Weather Service categories for gauge RDOM4, issued by WFO APX. Impact statements are the NWS's own wording for this location, reproduced verbatim.
-
Major flood 9.0 ft
-
Moderate flood 8.0 ft
-
Minor flood 7.0 ft
-
Action 6.0 ft
- Right now 3.52 ft
NWS forecast: 3.50 ft by Jul 29, 12:00 AM UTC.
12 months of flow at Grayling
Daily values from USGS gauge 04136000. Provisional data, subject to revision.
Highest crests on record at Grayling
| Stage | Flow | Date |
|---|---|---|
| 8.88 ft | 4,835 CFS | Apr 14, 2026 |
| 6.88 ft | 3,200 CFS | Apr 15, 2014 |
| 6.69 ft | 3,049 CFS | Oct 24, 2017 |
| 6.66 ft | 3,300 CFS | Apr 1, 1998 |
| 6.39 ft | 2,980 CFS | Apr 7, 1997 |
| 6.18 ft | 2,770 CFS | Apr 1, 2016 |
| 6.06 ft | — | Feb 11, 2021 |
| 5.99 ft | 2,730 CFS | Apr 19, 2013 |
| 5.95 ft | — | Dec 27, 2008 |
| 5.92 ft | 2,517 CFS | Apr 1, 2025 |
Historical crests published by the National Weather Service for this gauge.
About Au Sable River at Grayling
This gauge measures Au Sable River at Grayling, Michigan — the reading paddlers, anglers and outfitters on this stretch check before committing to a shuttle.
Holy Waters; livery cluster and the Canoe Marathon.
Raw CFS means little on its own, so every reading on this page is shown against the USGS median for the same calendar day — 625 CFS for late July, from 36 years of record.
Because the National Weather Service also operates a forecast point here, the page carries the official flood-category ladder and the NWS's own stage-by-stage impact statements.
Au Sable River at Grayling — common questions
What is the current flow on Au Sable River at Grayling?
As of the last reading on this page, Au Sable River at Grayling was running 1,030 CFS at a gage height of 3.52 ft, or 165% of the USGS median for this date. The number updates automatically from USGS gauge 04136000, which reports every 15 to 60 minutes.
Is that high or low for this time of year?
The USGS median flow for late July at this gauge is 625 CFS, calculated from 36 years of record (1909–2026). Comparing today's reading against that median is the only way a raw CFS number tells you anything — 200 CFS is a drought on one river and a flood on another.
How often does this reading update?
USGS transmits from this gauge every 15 to 60 minutes. This page bakes in the most recent reading when it is rebuilt, then refreshes live from USGS when you open it. Readings are provisional and subject to revision by USGS.
What is a runnable level on this stretch?
riverlvl deliberately does not publish a runnable range. American Whitewater and the local paddling community maintain the correlations for this reach, and they are the authority. This page gives you the raw inputs — current CFS, gage height, the seasonal median, and the 12-month hydrograph — so you can apply whatever range you trust.
How fast can this gauge come up?
This is a free-flowing gauge, so it rises with rain in the basin. The 12-month chart on this page shows the shape of the past year's rises, which is the best available guide to how flashy this particular reach is.
Where does this data come from?
The flow and gage height come from USGS gauge 04136000, public-domain data from the U.S. Geological Survey. The flood categories, impact statements and forecast come from the National Weather Service's National Water Prediction Service, gauge RDOM4.