Death Wears Grey — Charles R. Pike

Riding through New Mexico, bound for St Louis, Jubal Cade comes upon the remains of a bushwhacked wagon train. And the promise he makes to the last, dying survivor places the deadly doctor at the heart of the strangest mystery he has yet encountered in the savage West. A mystery that takes him through gambling joints and prison cells, to a trek across the bone-bleached flats of the Great Salt Lake, to a weird friendship with a one-legged old-timer and his murderous mastiff. And over it all hangs the specter of an albino general who believes that the Civil War is not yet over...