Does anyone know the origin of the word "yoo-hoo"? I would appreciate your help.

Probably lola you've already been there but if not

http://onelook.com/?w=yoo-hoo&ls=a

thanks, Dale.

Onomatopoeic yodeling, I'd wager.

Thinking about it, is that even possible??

Not on the Great Plains.

Actually, this is pretty much what I've been thinking. Certain kinds of sounds carry better over distance, and I understand that the ooooooo (as in who) is one of them. (I read this years ago in Careful, He Might Hear You {I think}; it takes place in Australia, and in it a lady gives this as the explanation for their Coo-ee call.)