The Old Spanish Trail runs around the south end of Death Valley and would have been an ordeal, but somewhat sensible with a good guide. The trouble started with a bad map (by John Fremont) that showed a non-existent "east west dividing range" that would take the to Walker Pass and cut off a good bit of distance.
The book "Death Valley, a Land of Illusion" gives a detailed account starting on page 39. I have read it many times and been curious about varioius points along the way and whether I could locate them on a modern map.
It is a bit surprising to me that it is not easy to find good maps to indicate the path of the main trail as well as the various parties who wandered into Death Valley.
In a general sense, using major cities and features that exist today, the route went from Salt Lake City, south to Cedar City in Utah, then to Las Vegas, Nevada, then through the Mohave desert to Cajon Pass and what would now be San Bernardino, California.
Stump springs is somewhere in the Pahrump Valley.
Two key points in the Mohave Desert are Resting Springs and Bitter Springs.
Resting Springs is about 4 miles east of Tecopa in Inyo County, as the south end of the Resting Spring Mountains.
Salt Springs no longer exists as a spring, it was buried by a 20th century flood that came down Salt Springs Creek. The location is only 0.5 miles from Highway 127 near where the Saratoga Springs road branches off heading into the south end of Death Valley. This is not Saratoga Springs. This is the location of the infamous Salt Spring gold mine. South of Salt Springs, the route skirted the east side of the Avawatz Mountains.
Bitter Springs is now on the Fort Irwin Army base, so you won't be able to pay a visit. The Springs are pretty much directly west of Baker and about midway between Baker and the Fort Irwin headquarters. They are fairly close to the east boundary of the base and west of the Soda Mountains.
They set off on October 7, 1849 from what is now Provo, Utah. The "regular route" took them pretty much south to what is now Cedar City.
Tom's Outdoor Info / firstname.lastname@example.org