I too live in Colorado and use on set of tires for all conditions (trail, mud & snow) and have found the BFG A/Ts to be an ideal Colorado tire. I have owned several sets of non-siped tires (M/T & MTR) and would never own another set for Colorado winter driving without having them siped. If you ran your Thornbirds in winter icy/snowy streets you know what I am talking about.
02 GC Overland, 4" RCLA, 4.5 Clayton Springs w 3/4spacers in front, Bilstiens, JKS Tracbar, Addco rear sway bar, Proto Fab Hi Clearance bumper, Smitty built 8,000 w/Syn
Previous Jeeps: 57 Willys, 74 J-10, 76 J-20, 80 CJ7, 91 XJ, 97 ZJ, 97 TJ, 00 TJ, 06 LJ Rubicon, 2010 JK Rubicon 4dr.