Yes, chain are definitely allowed up here... it is a requirement to carry them on commercial vehicles. I will let you decipher the "legals" but "generally" the requirement for chains are for commercial vehicles.
Realistically will you need them? Probably not, but I am not saying don't get chains. If you had a SRW the need is even less because of more weight force on a singe tire instead of spreading it over two. Many times I have gotten around more than just fine with my camper on in 2WD with no trouble at all. I do have good deep lug MS tires though. The weight of the camper is a huge advantage over unladen pick-up alone. If it were truck alone, then 4WD or chains in nasty condition is almost a must.
For peace of mind, it would be prudent to grab a pair. Check out
TireChains.com for a good varied selection of types for almost all tires. Good info in the FAQ section.
HERE is some good law information as well as
Colorado specific information.
I think you will be fine, but that is only my opinion. I have never chained up only my rear axle and very rarely have I needed to chain all four- those were off road in 2+ feet with the weight of the camper... weight is a huge advantage.
We are used to the snow up here and as mentioned a storm with many inches is coming down now. Municipalities and CDOT need to do a decent job of clearing roads to get your skier money coming in.
Best advice I can give is be smart about winter travel. If you can wait out the road condition until they are clear is perhaps best... easy to do with your own "hotel room" on the back (I have done it many times.)
Enjoy your visit out here!
Sold the TC, previous owner of 2 NorthStar pop-ups & 2 Northstar Arrows...still have the truck:
2005 Dodge 3500 SRW, Qcab long bed, NV-6500, diesel, 4WD, Helwig, 9000XL,
Nitto 285/70/17 Terra Grapplers, Honda eu3000Is, custom overload spring perch spacers.