A cowboy riding across the desert sees an indian lying naked on top of a sand dune with his hard-on sticking straight in the air.

The cowboy rides up and asks the indian: What ARE you doin??
the indian says: Me tell time.
How you gonna do that? asks the cowboy.
Sun cast shadow 'cross dick, Tell Time! says the indian.
the cowboy rides off shaking his head and says: Whatever!??

After a few more miles the cowboy comes across another indian laying naked on a sand dune with his dick straight up in the air.
The cowboy asks: Ok, now what are YOU doin???
the indian says: Me tell time.
How you gonna do that? asks the cowboy.
Sun cast shadow 'cross dick, Tell Time! says the indian.
the cowboy rides off shaking his head and says: Yeah, RIGHT!

a couple of miles later the cowboy sees an indian sitting indian style on a sand dune jerking off like there's no tomorrow.
The cowboy asks: I hate to ask, but what do you think you're doin???
the indian replies: Me Wind Watch