Should try the "Cool Hand Luke" trick - jump in a stream and run along the stream bed for maybe 1/4 mile, climb out on the same bank that you entered, then run a big loop back to where you entered, jump back in and run along the stream bed in the same direction as before but this time make it 1/2 mile before climbing out and continueing. The dogs should then just keep circulating around the loop using your entry point and first exit point.
I always remember the dog handler's lament, " Heee's ruuuun ol' Bluue tooo deeeaarth!"