Two almost back-to-back log jams are blocking most of the Green River about 2½ miles downstream from Flaming Geyser State Park, according to the King County Sheriff’s Office.

The jams contribute to an already-deadly river; at least two people have drowned this spring and summer due to the high, fast flow of the river. For a time, the Green and the Cedar River were closed to recreational use because of the hazardous conditions.

The Cedar also has log jams, including a major one caused by a slide triggered by the Nisqually earthquake near Ron Regis Park. That log jam is well-known to frequent river users, but still poses a hazard.

Sgt. John Urquhart, a sheriff’s spokesman, said the office is not aware of any new hazards on the Cedar.

The danger with log jams in a fast-moving river is that unsuspecting inner-tubers or other users of the river will be swept into and under the log jam, according to Urquhart.

The Sheriff’s Office is posting signs along the Green River warning of the danger ahead from the new log jams. Anyone using the Green River is advised to take-out no later than Metzler Park, an undeveloped park at about 186th Avenue Southeast off the Green Valley Road.

Users of the Green River, and all western Washington rivers, should use extreme caution, according to Urquhart, because rivers are running fast and high and are still very cold.