I was pretty impressed with how quickly and where the Fastfind 210 got a GPS fix when I assisted Doug in his recent testing (which somehow found me in a pool getting sprayed in the face by Doug wielding a garden hose). I can't tell you if it would get a GPS fix in that canyon, but I would bet my life on it getting a fix anywhere a Garmin GPSMAP 60CSx would. I would not be surprised if it achieved a GPS fix in areas the 60CSx would struggle.