“The old Hidden Valley lift line; a bit steep on the way up!”
— Jared Crockett
This ascent is within Rocky Mountain National Park. It is at the old Hidden Valley ski area, which closed in 1991. It is a ski area no more, and is now being returned to the forest. RMNP has a great warming hut and restroom facility at the base, along with ample parking. This area is very popular for the sledding hill not far from the hut.
Beyond the sledding hill is where the old ski runs used to be cut through the trees. This track follows one of the old lift lines for the most part (the "Lower T-Bar" lift). This particular ascent is quite difficult. I did it in snowshoes with a snowboard strapped to my back. It was a real workout! It will take you a fair amount of time to climb up this, especially if there is deep powder (and if you're lucky, there will be!).
Just take your time, try not to overheat, and enjoy the beautiful scenery. Take a glance back down every now and then and just imagine how you'll be blazing back down that track before long!