The South Fork of the Eel River and the Main Stem of the Eel wind over 30 miles through the park and offer excellent swimming, boating, and fishing. The South Fork is dependent on rainfall for its water, and can swell quickly and dangerously following a heavy rainstorm. All visitors are cautioned to respect the river and to use proper water safety at all times.
During the summer, nothing is as refreshing as a cool dip in the river. Good swimming holes include Lansdale Bar, Eagle Point (near Hidden Springs Campground), Williams Grove, Garden Club of America Grove, Gould Bar, and Leatherwood Bar.
The park does not provide lifeguard service—please use caution. Though the water may look calm, it has claimed lives in the past.
In late summer, the river often has blooms of blue-green algae, which can be hazardous and even fatal if ingested by pets or small children. When the river flow is low, check for algae warnings.
Summer flows are usually too low for boating but springtime brings great kayaking and canoeing. Because river flows change radically depending on recent rainfall, it can be hard to plan ahead. High flows combined with woody debris in the river can be hazardous. Determine river conditions before starting out and make sure your skills are up to the challenge.
Before boating, check flow conditions at the USGS Miranda River Gauge at the south end of the park. If the flow indicated is above 6,000 cubic feet per second (cfs), only very experienced paddlers should enter the water. From 3,000 to 6,000 cfs you should have very strong paddling skills. Below3,000 cfs is generally calm, and anything below 300 to 500 cfs will be too low for paddling.