1. There aren't that many of them when compared to the big schools.
2. Did you troll through practically every single faculty-member's profile at these big institutions?
3. After one gets into any of the prestigious schools for graduate work, then your undergraduate institution doesn't really matter directly in your employment anymore. Once you are at MIT, then whether you got your undergraduate degree from Princeton or Swarthmore College does not matter anymore in whether you get a postdoc or employment. Your PhD work is what matters the most.
Off the top of my head, Thomas Cech is a Nobel Laureate in Chemistry, and he received his undergraduate degree from Grinnell College. Can't do much better than that!
Zz.