Lonnie, there is not an issue at the heights they are jumping at. There is a technique used in the military called HALO (High Altitude Low Opening) which is used to insert people undetected where you jump from +30,000 feet and open the shoot at about 300 ft. That needs an air supply. And if i remember rightly a change of underwear

It doesn't matter what height I jump from. If I didn't open the chute until 300 feet, I'd definitely need a change of underwear!!! 
Anyway, I was wondering what altitude they were jumping from because you mentioned Nevada and California, and with that lake down there I figured they were probably near Las Vegas, which means one of those mountains down there is Charleston, at just under 12,000'. And, in the video it looked like they were closer to the moon than the mountain top when they jumped... 







