There are only four common use 70cm simplex frequencies assigned in Utah.
And 447.850 is only used around Salt Lake City and reserved for other uses in the rest of the state. The Utah coordinators have dedicated much of the spectrum often available for simplex to repeater control, repeater linking and other stuff.
Point being there are no overlapping Colorado and Utah FM simplex frequencies in the band plans that I can see other than 446.000 MHz.
"Silent enim leges inter arma." -- Cicero