I finally made it to Kramer Arch, east of Barstow, CA. I've tried to get there before but my previous car (Acura MDX) wasn't up to handling a short section of road that's seriously rutted. My new Land Rover drove right over it without any problems. Gene and Bobak were with me on this trip. We were on our way to Zion NP, and this made for a nice diversion along the way.
That's Gene in the photo, standing on top the arch. Here's a Google map centered on the arch location. I approached the arch by taking Mule Canyon Road and Phillips Drive, both of which are sandy washes. To make things interesting, I left by continuing on to the east, following a road / ATV trail until it met up with E. Phillips Drive. We got the truck to the best pitch angle so far: 27 degrees down. The roads always seem much steeper than my inclinometer shows. I've begun to wonder if the truck's automatic leveling suspension is possibly negating some of the steepness sensed by the passenger compartment (and my inclinometer).