My thoughts from looking at their two licenses that they have granted to them (
KYU980 and
WQBX487) is that they have plenty of room to pick and choose the mode they operate MRA 2 on. Among those licensed for MRA 2 includes operation of a repeater for MRA 2, as well as fixed (FB) and temporary (FBT) base stations. What interests me is the odd FX1 stations for 465.6250 MHz which believe are typically licensed for repeater inputs and rather restricted number of MO units they have operating on that UHF frequency. Given that no one has noted the input frequency for the MRA 2 repeater makes me think that perhaps MRA 2 operates in mixed modes, normally operating as a simplex frequency (which explains lack of hearing the repeater in Broomfield) with an option of a crossband repeater being used for wide area coverage. The limited usage may indicate that it is restricted to someone in a leadership position for things like membership announcements or important operational messages.
The simulcasting thought isn't a bad idea either, given that WQBX487 shows another repeater in the Longmont area operating at 159.2325 MHz. However, the Longmont location does not have a license for a repeater on MRA 2. I don't think the online feed is streaming that since it remains unlisted by both the feed and RadioReference (likely due to lack of positive identification for its usage).
A slightly unrelated noted is that Boulder County does have at least one example of mixed usage operations on a frequency. It can be seen with the Boulder Fire Department which has a setup with repeater and simplex operations simultaneously on 155.7825 MHz (Fire-2/Tac-3). I've once heard the Battalion Chief having units switch to Tac-3 for a working fire (noted along with my inability to hear working companies), yet I was able to hear the Battalion Chief loud and clear as if she were operating on the Fire-2 repeater. Perhaps Boulder Fire Department used Rocky Mountain Rescue as an example for using repeaters to supplement operations without being dependent on them.
EDIT: I did some extensive searching of Rocky Mountain Rescue related things online as well as explored the KYU980 license thoroughly to try to figure out more about the MRA frequencies. It appears that Rocky Mountain Rescue has plans in 2002 to build a repeater system but was told that there were not sufficient VHF frequency pairs to allow them to do so at that time. They did note that they would be purchasing repeater equipment in 2002 with grant money they received. It appears that the license in 2002 only contained MRA 1 and MRA 2. They also mentioned adding "MRA 3" to the license for out of county use (misprint?), but no idea what they meant by that and it has never been mentioned since. They also mentioned "adding a new way of controlling or using the 1900 base station radio via a UHF link." Not too much has changed regarding the KYU980 license since then besides adding the UHF control frequency and the additional 159.2325 MHz frequency licenses sometime in 2004-2005. There was mention in 2005 of hearing Rocky Mountain Rescue on their UHF frequencies on portables
on the forums.