To cross the riffle; metaphorically, to attempt a thing successfully.
1859. I guess theyll make the riffle.Mrs. Duniway, Captain Gray and his Company, p. 235 (Portland, Oregon).
1862. See Appendix XIV.
1875. If I can make the riffle I want to git to Washington Territory yet.S. J. Barrows, The Northwestern Mule and his Driver, Atlantic Monthly, xxxv. 557/2 (May).
1887. (Lit.) We ran on, fighting the stream at intervals, but making the riffle, or crossing the rapid, without resorting to bacon hams in the furnace or a nigger on the safety-valve, as was the custom in the palmy days of steamboat racing on the Mississippi or the Sacramento.M. Roberts, The Western Avernus, p. 202. (N.E.D.)
1902. I dont want to kill a man fer jest tryin to steal an not makin the riffle.W. N. Harben, Abner Daniel, p. 230.