Before trying Castle and Conundrum, I drove up the 4wd road the evening before. The road goes way up on the mountain, and can make for a very quick climb if you have a high-clearance 4wd vehicle and drive all the way to the end of the road. I drove up above tree line, "camped" in the car, then took off once it was light. I started by hiking a mile or so up the remainder of the mining road, which ends at a big flat area which would be great for parking if you make it all the way there. It's not too bad of a road compared to, say, the Nellie Creek road or the road to Crystal.

From the end of the road, cairns will lead you across a boulder field to the base of a headwall. There's really not much a trail here, but the route is pretty clear.

Your next goal is to get up this headwall, above which is the upper basin underneath Castle and Conundrum. Even in early August, there was snow in plenty of places. I'd stick to the rocks as much as possible. Once up into the upper basin, a trail suddenly appears on your left. This is really the only clear trail on the route, and takes you up to Castle's Northeast Ridge.

The path up the ridge is part walk and part class 2 / 2+ scamper. There are some cairns to help, but it's not a tough route to find. Just stay near the ridge crest.

As you near the summit, you will lose some elevation before the final push. Once on top, enjoy the views of the Elk range! Views from the summit:

From the summit of Castle, you could turn around, but quasi-official 14er Conundrum is close by.

I headed on down to the Castle / Conundrum saddle. The route is somewhat loose, but simple to follow. Note the spot at the low point of the saddle with red dirt, at the top of a gully filled with red dirt that leads down into the upper basin. This is one choice for your descent.

From there, simply scamper up to Conundrum.

Views from the top of Conundrum:

Conundrum has two peaks separated by a ~50-foot notch. From what I've read, the northern (far) summit is a little higher, but each summit looked higher viewed from the other. Maybe that is the conundrum.

For the descent, you have two choices. You could head back the way you came over Castle's summit. This is longer and has a bunch of extra elevation gain. Or you could descend to the previously mentioned red gully leading down from the low point of the saddle. You can descend the steep, loose red gully, then cut straight across the basin, back to the bottom of the trail leading to Castle's ridge. This is shorter and requires very little elevation gain, BUT the red gully is very uncomfortably steep and loose. It doesn't have an official name, so I'm suggesting "Satan's Butt Crack". And once you're clear of the nasty gully and walking across the basin, the rocks in the basin are very, very loose as well. Progress is difficult. I went down Satan's Butt Crack with some difficulty, and then slowly made my way across the loose, sliding rock of the basin. You'll want to angle left of the lake, aiming for the bottom of the clearly visible trail to Castle's ridge. Honestly, this was the most difficult part of the climb.

There is no trail and no cairns in the basin, so you're choosing your own path. Thankfully, you have a strong view of where you are going, and there aren't any surprises on the way. Once you reach the trail again, simply retrace your steps down the headwall, across the boulder field, and back down the road.

Castle and Conundrum is a great medium difficulty climb, and the easiest of the Elk 14ers, and you can adjust the difficulty depending on how high you drive on the old mining road! The biggest choice here is whether to descend through Satan's Butt Crack or back over Castle. They're tough in different ways. Some routes seem to tell you to climb UP that gully, such as if you're climbing Conundrum by itself, which I can't recommend unless it's a snow climb. It's too steep, too slippery. I mean, I'll bet it's possible, but I don't think I'd want to try it.