On Saturday morning, we followed the Rainbow Trail (to the south) for about 5.5 miles to the intersection with the Hunts Lake trail. The Rainbow Trail would prove to test us both on the way in to the climb and on our way out as it continually undulates along the landscape gaining and losing and gaining and losing several hundreds of feet of elevation. The Hunts Lake trailhead is at the top of one of the many ridges and is noted as an "unmaintained" trail on the Trails Illustrated map. Indeed, it was. It begins as an old road that has become overgrown with grasses, trees and bushes as it zigzags its way to the Hunts Peak drainage. We backpacked for about 1.5 miles to the first water and creek crossing where we found an idyllic camping spot under a wonderful tree. You could tell this is a rarely visited area and we saw no one on this hike or climb.
On Sunday, we crossed the creek and continued on the "road" until coming to a "climbers trail" which climbed steeply towards Hunts Lake. The terrain and trail leveled out for a bit and then climbed steeply to the lake. The "trail" was easy to follow and was flagged with pink ribbons from time to time. Hunts Lake is a beautiful deep blue lake with absolutely no signs of life in it at all. Maybe there's fish, but we didn't see any. There are good campsites (though limited in number) along the north side of the lake. Hike around the north side of the lake until you get past the trees and can easily ascend the northeast ridge coming down from the summit. We made it a bit interesting by sticking to the rock outcroppings instead of just walking up the grass. Once on the ridge, turn left and walk to the summit. There was a register there (in an old jar) that was put up there about 5 days before we arrived (amazing). We returned by descending the northwest ridge to a low saddle and back down talus fields to the lake. It was probably about 2.5 miles from where we camped to the summit. After getting back to camp, we packed up and backpacked back to our truck arriving at around 7:00 p.m. Those ups and downs on the Rainbow Trail were a grunt after such a long day. This was a pretty climb, though, and pleasantly remote. A best guess would probably be about 20 miles roundtrip and adequate (if not just too darned much) elevation gain. Happy Trails!
John B Pelner adds:
You should have searched the maps better. There is a short steep route up Hunts (and Bushnell-Twin Sister) on the west San Luis Valley side. Study the Rio Grande Forest map and you will see the forest roads that get you to the bottom of the West side drainages. You'll still be alone, but with more time to relax at the end. The Rainbow trail is nice but a pain in the butt.