First of all, survival without any of the modern amenities in this climate would be very different considering what state we are in our technological evolution. One of the base things we need to survive is water. Streams can be found in the Rocky Mountains from snow/ glaciers melting and or small Alpine lakes formed in mountain cirques. Second, you need food. There are many meaty animals in this biome because of the cold. For instance, you could eat a large Mountain Goat for dinner and a Collared Pika for a snack! You would also need shelter. The mountains have large rocks that you could hide under for the first few days but you would probably get WAY too cold as during the night its almost always below freezing. You could also always just bring a tent and a mummy bag. It would be beautiful up there wouldn't be much to do after a while, I think. I fell it would be exhilarating for the first few days or weeks but then it would be a little boring for me. But also I've never been before so I don't know.