First let me say that I am not a fish biologist and I am just passing along information I have read. However, I have caught California Golden Trout.
The California Golden Trout originated in the Kern Plateau. This fish are a subspecies of Rainbow trout that live at 8000 to 12000 elevations. They have been transplanted to Wyoming and New Mexico. The biggest fish every recorded came from the Wind Mountains in Wyoming.
There are other yellow trout but they don't have the color or markings of the California Golden Trout. Most yellow trout come from hatcheries and are also some form of Rainbow Trout. So you might say they are related but definitely not the same as the California Golden Trout.
California Golden Trout