If high-water flows and extremely cold water haven’t proved deadly enough this year, another hazard is threatening users of the Green River.

This time it is two logjams, blocking most of the river, about 2½ miles downstream from Flaming Geyser State Park.

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 logjam, the King County Sheriff’s Office warned.

The river current will pull the person under the jam, sometimes moving them to the other side, but more often keeping them stuck under the water. Then the person drowns.

The Sheriff’s Office is posting signs along the river warning of the danger ahead. Deputies are advising people to get out of the river at Metzler Park, an undeveloped park at about 186th Avenue Southeast off the Green Valley Road, to avoid the logjams.