Based on my research, it seems that what I want to do is not possible, but in case something has changed, I wanted to check to see if anyone had come up with a way to do thi
This will work in some browsers, not not all. I don't think there is an elegant cross-browser solution
Include the print footer/header you want in divs on the page (in this example div id='printableFooter')
In the screen css file put:
#printableFooter {display: none;}
In the print css file:
#printableFooter {display: block; position: fixed; bottom: 0;}