I've been doing some searching also and I found this permit pulled for the tower just down the road from me.
2013000260 3/5/2013 $0.00 TELECOM SITE 17360 RD E-16 CONTINENTAL, OH 45831
Alteration /REMOVE AND REPLACE CABINET, Alteration - Addition /REMOVE AND REPLACE ANTENNAS.
Sprint is the only one on the tower, I have also found some more being pulled in the Toledo Market