riffle

The river was low, but not fordable except at Coxe's Riffle, a few miles below Steubenville.

We might have made the riffle, I guess, if Denny hadn't played out and tumbled from his saddle.

He watched the two Lhari riffle through his papers with their odd pointed claws.

Riffle—A groove or strip to catch gold and mercury in a sluice.

I'll go in just below the riffle and explore the cellar-hole!