http://weber.edu/greeks/
All Greeks are local, except for the Mormon sorority which has a few chapters across the U.S. Only one, Lambda Delta Sigma (LDS) uses greek letters. There are 3 LDS chapters on campus (don't know what's up with that).
There are 2 national fraternities on campus.
There appears to be a Sigma Gamma Rho chapter, but they are not listed on the Greeks page.