If I'd known there would be forum interest in the details of my jaunt I would have documented better. I did not take any images of the dry fall below or above.
I don't know where the old assay office is but I parked about half mile in from the exit of 20 Mule Road to the pavement. The spot has a drive off where three or four cars can park off the south as the dirt road curves east to north and where the main draining wash heads down alongside the road.
It's a lovely hike up the wash with just a few scampers up some sloped dry falls until to stay left and hit the main obstacle/dry fall. Just prior to this main dry fall is another very steep and impassable dry fall to right hand. On a prior trip, I explored down that small drainage to the top of this dry fall. One would need ropes and gear to ascend or descend.
So back to the main dry fall. I've bypassed it three times now. The first time was crawling up the very steep scree field to the left and scooting well above the dry fall and back south/right into the wash above the dry fall. The second time was even more difficult crawling on all fours up the very steep clay slope to the immediate right/south of the dry fall. The third time and most recent of mention in this video was a repeat of the first time. The return in the video is over back over and down that same scree frield.
I intend to eventually summit the Blue Mountain via a route from Artist Palette circling around its base from south to east to its north ridge. I'm fascinated by the blue color and the geology, i.e. that "Z" shaped pattern on its north ridge face. It's fun being out there because it's so isolated.
You wrote: "Very few others have ever been up there given the confusing badlands maze-like terrain with difficult sections to overcome, though would not be at all surprised if some other of you locals on this board have."
Thanks for the link to your jaunt through upper Artist Palette to Borax Benchmark. Your images of the geology and flowers are real eye candy. I had forgotten about a prior video I made covering similar territory a few years ago: