A mile or so past lower cache called the Delta Overlook. On your left when headed up trail there will be a somewhat overgrown side trail into the trees and you may even hear rushing water somewhere.
Trail ends quickly and you can walk toward that rushing sound. Must be the real Alkali Creek!
If you wish to continue on the main trail and climb further up be aware that the most challenging narrow rocky climbs will be next and only experienced riders should take this on. trucks probably can't make it. At the top of this lengthly gnarly climb you will reach a beautiful open meadow and a sign placed by the Delta Search and Rescue..and another cache. None of this trail shows on the topo maps...but you can go all the way to the intersection with the Pipeline Trail that comes up from the Devil's Thumb golf course as we have met even trucks coming up that way although we hear it is very very tough for them.