Subject: Why does rivers (springs) always come from a mountain top ?

My family and I did a camper trip to Colorado. We came to that point, where 
the  waterdivide was. A ranger told us, the Colorado River has it spring on top 
of the Rockies like most other rivers, too. My question is, why does the water 
is going up a mountain first and coming down as a river. I couldn't find any 
information about it. Please help, I want to do a science project about it.

Re: Why does rivers (springs) always come from a mountain top ?