Thunder Mountain wrote:
As 36 year resident of Colorado's high country and a 30 year resident of Estes Park, I can tell you May can be a tough travel month. In Rocky, Trail Ridge Road in all likely hood will not be open. Traditional opening date is Memorial Day weekend. Can be a little earlier in a drought year.
You did not mention what your activity expectations are. Bear Lake will have some leftover snow. Lakes above will probably be frozen or partially frozen. Trails will be icy in the morning and slushy in the afternoon. Or you can have a really warm May with many trails more accessible. If you are only a car tourist interested in scenery, May is ok. You will miss the summer crowds in places like Estes Park and Aspen.
I remember a mid May storm in Estes Park that dumped almost 3' of snow with temps in the teens. I also remember a Memorial Day weekend storm with a couple feet of wet snow that shut down most roads. We called those storms "May dumps" then again it may not dump! I remember many beautiful warm and dry Mays. Snow storms that shut passes are not uncommon into early June.
The bottom line is that May can be very unsettled. Bring shorts, heavy coats and everything in between. The good news at the storms are usually quick hitters with the snow melting in 24-48 hours. Just stay informed and be prepared to hang out.
^^^^^ This.
This season, Trail Ridge didn't open until Memorial Day weekend, when the plows finally broke through, only to have it close down again. I was up there the weekend afterward, and the snow walls were 15-20+ feet high in places, and they closed the road in the evenings when the temps dropped below freezing. Camped in Moraine Park CG in RMNP, it was chilly in the evening, but no snow in the CG. Glacier Basin CG, at a higher elevation, didn't open until later in June.
Be aware also that one of the main access roads (US 34 through the Big Thompson Canyon) to Estes Park and RMNP is undergoing a major reconstruction project; it is currently under way with some minor projects, and the main project gets going full throttle in October 2016. There will be some complete shut downs of the road during certain periods of the construction project, and the main portion of this project is scheduled to run until May 2017, weather dependent. The entire project will not officially be complete until 2018 or 2019.
CDOT is working on recommendations of residents and businesses in the area to try to have a shorter construction period with full shut downs, than to try to keep the road open to limited traffic and have a longer construction time. Last update I received on the scope of the project indicated that they planned to have the majority of the main reconstruction finished by late May 2017, in time for the tourist season.
Alternative to getting to Estes Park/RMNP on the east side is US 36 from Lyons, which in turn can be reached via CO 66 from the north exit for Longmont off I-25
You mentioned in your follow up considering locations within 100 miles...presumably of RMNP? If that's the case, then consider Boyd Lake State Park in Loveland, if you can get by with just electric connections (common water and dump station on site), or St Vrain State Park outside of Longmont, at the I-25 exit for CO 119. Both are very nice parks.
I also usually recommend Riverview RV Resort west of Loveland, but in light of the construction going on in the Big Thompson Canyon/US34, this may be considerably out of the way for you.
You could also consider staying on the WEST side of RMNP, but you'd have to access via I-70 to US 40, up and over Berthoud Pass to Winter Park, and then on up to Granby and Grand Lake. There's a couple of fine commercial CG in Grand Lake, there's Timber Ridge CG inside RMNP (all first come/first served-no reservations accepted), and about a half dozen USFS CGs on that side that are really nice. An advantage of being on the west side would be that you're not limited to RMNP (admittedly not quite as scenic on the west side), since you'll be close to the Summit County area of Dillon/Frisco/Breckenridge as well as Hot Sulphur Springs. AND once again, weather will be a factor. That west side can get lots of snow, so the season for camping will be snow dependent. Some of the USFS CGs are along a major lake over there, and it's a bit lower in elevation, so the snow melt may be sooner, if it's a somewhat normal winter.