On May 5th, 1862 Confederate Soldiers, that were stationed in Tucson, were attacked by Apaches at Dragoon Springs (an abandoned Butterfield Mail Station). These Confederates were on a foraging mission at the time.
The resulting desperate fight appears to have lasted a few hours. The soldiers sought protection by holing up in the stations ruins while fighting for their lives.
When Cochise and his warriors broke contact, they had killed 4 Confederates and stolen several horses.
These soldiers were buried at the Dragoon Springs Station. (in modern day Arizona)
Ironically, Union troops were fighting side-by-side with the Confederates in this engagement. It is believed that the Yanks were prisoners of the Rebs who were used to provide labor on this foraging mission. When ambushed by Cochise, firearms were distributed to every white man to help fend off the common Apache foe. In fact, it was a Union soldier who carved the Confederate names into the headstones.
To the best of knowledge, this occurrence resulted in the furthest western Confederate deaths of the Civil War.