OK, I'll stick my neck out.
Horses easily get over Cottonwood Pass to Chicken Springs Lake. There, there is a ramp that slants up and left to higher country (see picture), that a horse might manage. If not, there is gentler terrain just out of sight to the left. It seems possible to go one of these ways and gain the Sierra crest between Trailmaster Peak and Peak 12525. Then travel just below or on the crest to Cirque Peak, then around to the top of New Army Pass and on to Langley.
As far as using dynamite in that instance, I understand that is how they used to dispose of horses that became crippled or died in the back country. Perhaps still do. I've always wondered why they didn't just have a really big BBQ instead. Other ideas include flying the carcass out by helicopter or flying in machinery to dig a sufficiently large grave, but I'm sure these are rejected on the basis of cost and effort, for just a horse.