Looks like Sprint has started pulling permits in Arkansas (I'm not 100% sure that the ones pulled in January are Sprint's - there's no contractor/owner name listed; however, the costs match the Sprint permit from February):
Edit: I checked both addresses from the January list in Google Maps Street View - both are cell sites. However, there is a possibility that they are AT&T's, as AT&T is building out its LTE network in the same area right now (I was actually trying to locate AT&T permits - most of those have been for $47,000).
5006 West Main: http://bit.ly/ZFcyLE
907 East 3rd: http://bit.ly/13rH4xJ