This is the Park County Courthouse in Cody Wyoming. The older part of the courthouse was built in 1912, and replaced an earlier courthouse. The newer portions of the courthouse were built in 1983.
In my mind, the newer part of the courthouse is a bit unfortunate in terms of design, as it doesn't mesh well at all with the architecture of the older structure. It's one of at least three Wyoming courthouses where this has been done, with the other two being in Lusk and Sheridan. On the plus side, the older structure, which had been outgrown, was preserved by this approach.