Out here, the Sheriff's are allowed to carry pretty much anything they want. As far as I know, they all have .40's or .45's (mostly Sig's and Glocks). It is very rural here, so most likely they will be firing at deer or antelope that have been wounded by cars. I do know that neighboring Douglas County is only allowed .40 or .45.
Interestingly, it either Denver or Arapahoe county (can't remember) are not allowed to carry .40; 9mm or .45 only. The way I understand, it is a logistics thing and the department does not want to have numerous different caliber pistols to feed.