Mating california toads (Anaxyrus boreas halophilus).
The California toad is a subspecies of the Western toad.
Those were spotted in Darwin Falls (Death Valley National Park).
In Darwin Falls, California toads are known to hybridize with Red-spotted Toads.
For more information about California toads, read www.californiaherps.com/frogs/pages/b.b.halophilus.html and en.wikipedia.org/wiki/Western_toad