Rock - Worm Lake outlet to Sturgeon River (9.1 miles)

Rock, Michigan, US


Worm Lake outlet to Sturgeon River (9.1 miles)

Usual Difficulty II-III+ (varies with level)
Avg. Gradient 69 fpm
Max Gradient 145 fpm

Gauge Information

Name Range Difficulty Updated Level
Rock near Covington Approximation
virtual-130833 150 - 600 cfs II-III+ 00h45m ~ 32.0511 cfs (too low)
Likely too low for reasonable whitewater run. Virtual guage based on relative drainage of Rock at Hwy.28 vs. Sturgeon at Sidnaw. Correlation is not assured.
usgs-04040500 500 - 2000 cfs II-III+ 00h43m ~ 136 cfs (too low)
Likely too low. (~0-125 cfs) Expect flows to be 20-25% of this reference gauge on the Sturgeon. Always confirm actual Rock River flow via visual inspection of it's boater's gauge.

River Description

This river is far more continuous rapids than is typical of the Midwest! Do not take lightly the II-III rating! Paddlers should be strong, confident, intermediate paddlers, with an experienced group, before attempting this run at moderate to high levels. At such levels, most paddlers will be left with the impression of this river being essentially one long rapid, quite different from the usual pool/drop runs of the Midwest!

From the recommended put-in, a brief flatwater paddle brings you to some light rapids. Shortly you'll encounter a very low footbridge which will be a limbo at low-to-moderate levels, and will require portage at moderate-to-high levels. Soon thereafter the river assumes the character it will hold for much of it's length: essentially one, non-stop rapid. Trees in the current are not uncommon though usually can be paddled around. Be alert! As of April 2001 there was one beaver dam that could be 'snuck' by a paddle through the trees on the left.

While the 2.3 mile section above Hwy.28/141 generally does not exceed class II, it is recommended for it's warm-up value. If you are not completely comfortable with the style of boating you encounter on the upper reach, it may be advisable to abbreviate your trip at the Hwy.28/141 bridge. The pace decidedly picks up a notch downstream.

The river slows down a bit either side of the Hwy.28/141 bridge but soon resumes it's downhill race through the forest. The river is still generally class II, but you start encountering borderline III water the further downstream you proceed. As of April 2001 there was one large tree completely blocking the river. There is a brief respite in a swampy stretch that will warn you that you are soon approaching the most challenging section of the run. The river makes a turn to the left, tripping through waves and holes before turning sharply to the right at a rocky bend, where the action accelerates. This right-hand-bend often holds wood, though we've always been able to remove it to run the drop cleanly.

This drop signals the beginning of the steepest mile of the river. There is a wonderful rollercoaster ride of waves with a few lurking holes. Be on your toes and stay in your boat, as a swim here could take on epic proportions. This is a mile long class III rapid at medium to high flows. When the pace slackens off and the forest opens up, you will come to another low footbridge that signals the confluence with the Sturgeon.

There is a 3.4 mile flatwater egress paddle from here to the Plains Rd bridge on the Sturgeon. (This has been reflected in the length stated on the run name, but is not included in the "Length" or gradient figures in the description.)

Given the continuity of the whitewater and the ever-present danger of strainers on this small stream, the subjective difficulty is somewhat higher than the objective. Please exercise caution and discretion when paddling this reach, especially at higher flows.

Boaters looking for an additional challenge may consider finishing this trip by continuing downstream of the listed take-out to run Tibbets Falls on the Sturgeon (assuming the 'short take-out' is accessible.

AW members may click here for Part 1 of an article from the AW Journal, way back in 1981!
AW members may click here for Part 2 of the article.

The article describes the following:
Upper Presque Isle,
Lower Presque Isle,
Lower Black, Upper Silver,
Lower Silver,
Falls, and
Rock, (this reach)
and Wisconsin's
Lower Brunsweiler,
Montreal, W.Fk., and
Montreal Canyon.

StreamTeam Status: Not Verified
Last Updated: 2009-11-23 11:59:11

Rapid Summary

Mile Rapid Name Class Features (Legend)
2.3Hwy.41 / USGS site / Alternate put-in/take-outN/AAccess
4.4Main (largest) dropIII+
5.9Confluence with Sturgeon RiverN/AAccess

Rapid Descriptions

LOW BRIDGE! (Class N/A, Mile 0.3)

A property owner has a very low footbridge which will be a limbo at low-to-moderate levels, and will require portage at moderate-to-high levels.

Hwy.41 / USGS site / Alternate put-in/take-out (Class N/A, Mile 2.3)

USGS lists a sampling site at Hwy.41 with drainage area at this point of 40.3 square miles.

We generally recommend using the upper put-in (as listed on this reach). It gives boaters (especially those who may be less familiar with the run) a chance to 'warm up' and see what the run is like. If you have any difficulty or concern running the upper part of the run (down to this location), you should seriously consider taking out here. The run from here down steps things up a notch or two.

Main (largest) drop (Class III+, Mile 4.4)

As the river sweeps to the left, it approaches the most significant rapids/sequence. At low-to-moderate flows, this may be boat-scoutable. At higher flows, (and even moderate flows, particularly for less experienced paddlers, or those not well-familiar with this run) scouting is highly recommended. A tight bend partway down is prone to containing wood. Action is very continuous for a good ways downstream. Anyone having problems anywhere on this stretch will be in for a long chase if they end up out of their boat.

Confluence with Sturgeon River (Class N/A, Mile 5.9)

This is the end (mouth) of the Rock River, and the end of the gradient on this run. From here, you normally have three miles of pretty much dead flat paddle out to the usual take-out. Directly across the Sturgeon River from the mouth of the Rock River, there is a house. It may be possible to (and one time we were there, we did encounter the property owner, who volunteered that we could) take out at that property to skip the long paddle-out. However, finding the right back roads to get to that property is not easy, and (if I recall) there is a gate (well back from the property) which will be closed anytime the property owner is not present. Thus, I would not count on using that access to eliminate the flat water paddle.

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