I may have heard some encryption on their radio-to-radio P-25 channel 12 (168.6125) at one time otherwise everything else has been in the clear.
Search for "
Rocky Mountain National Park" on the following webpage:
Scanner Frequencies and Radio Frequency Reference for Colorado Federal (Colorado)
www.radioreference.com
The listing of frequencies for the park is a little over 3/4 of the way down the page.
Shawn