There are different LTE radios, but mostly in urban and sub-urban areas they use 1600-1800MHz thereabout. Some also use 1300-1400MHz. The LTE-LR is usually in the rural areas taking over the CDMA channels at 700-900MHz. There should be a listing available though your local FCC showing providers, tower locations, and services.
Issue for C-band is WiMax which is using an unregulated band up into the 3500MHz range. Smaller isolated internet providers often utilize this band for wireless access point/client services because it may not have license fees and is slightly above the polluted 2.4GHz wifi band.