I visited ruidoso new mexico and,the elevation was 7000 feet. my oxygen level dropped to 91-95 why? my wife was fine at 96-98?why did this upon to me?

Altitude: At altitude there is less atmospheric pressure and above 7000 feet in particular this can affect your oxygen saturation. The body can adapt to this decrease in several ways. As you descend slowly, these adaptations will help to control symptoms. Since you were both breathing air at the same extreme altitude, your lungs/body responded differently. If you have any symptoms, a workup can be done.