One (sometimes tricky) way is by using the Google Earth file located on http://www.opencellid.org/cell/map
I say tricky, as that shows you ALL the known towers from all carriers, distinguished by carrier SID; in a dense urban area, things get cluttered. To narrow it down, you need to know the SID of the Sprint towers in your area: OK City is 4164 in you guy's case.
[For anyone else:
To get this, you can look it up in the PRL file here, or alternately, see what your phone is connected to via the hidden diagnostic menu on your phone (*3001#12345#* for the iPhone. Can't remember what it is for the EVO or Epic- ##DATA# maybe?) They also have android apps that can tell you your SID]
Just look for towers in your area with that as the SID, and you are set. BTW, sometimes it might seems like a tower appears to be coming right out someones house! This usually just indicates that someone has a AIRAVE femtocell set up, though. Additionally, since this is crowd-sourced info, it may not be 100% perfect... but it is better than nothing!