Gunmen of the Desert Sands — Ralph Cotton

SIX-GUN FROM HEAVEN
When a Mexican girl shouts a warning in the midst of a gunfight, Fast Larry Shaw knows he owes her his life. That's a debt he may end up paying, because the girl believes he's the answer to her pleas for rescue from outlaws who have put her through hell. Shaw's no angel, but he is ready to give all the protection and hope a gunslinger can offer. Trapped in the cross fire between federates and banditos, Shaw's going to need all the prayers--and ammo--he can lay his hands on.