OverviewSphinx Mtn from TH to summit is 6287' to 10878', about a 4500' gain in elevation. The Helmet/Sphinx saddle sets around 9000'. TH to saddle is class 2, saddle to summit is class 3. I found the summit could be safely attained if reasonable caution is used by a moderately experienced hiker/climber. I had one slip on the way down the gully which caused me to catch myself by the palm of my hand. Nothing some advil won't help, and it might have been avoidable had I exercised more caution. There was a group I saw on the summit plateau who had several trail dogs with them, so evidently dogs can make it too.
TH to saddleI parked at the Bear Creek ranger station east of Cameron, MT. Once you turn off of 287 in Cameron, there are plenty of signs to lead you to the trail head.
The first 1.5 miles are a rather wet hike through some creek drainage, so I'd suggest wearing some sort of waterproof boots. Once the trail leaves the side of Bear Creek, it dries out plenty. There is, however, heavy overgrowth of wildflowers and grass spilling onto the trail throughout the meadows. It seems to be a reminder that you are off the beaten path, but the overgrowth could spell wetness if it had recently rained; in that case gators would be nice, but are definitely not a necessity. Once the grand meadow is crossed, the trail begins numerous easy switchbacks, beginning in forest and leading to sub-alpine meadows. When you come around a corner, the Helmet is in view for the first time. It is pretty awesome but gets even better the closer you get to the saddle. The easy switchbacks continue until the saddle of Helmet and Sphinx is reached.
saddle to Sphinx peakOnce the saddle is reached, there is an obvious transition from "hiking" to "here comes the climb". From the saddle, a look toward the Sphinx will reveal a climbers trail that follows the saddle ridge and leads through some small groves toward the gully, which you will get to know very well. Once the base of the gully to the Sphinx is reached, the climb becomes very class 3. Get ready for some scrambling. There is lots of loose rock and the trails were difficult for me to follow.
The trail stays on the left side of the gully for quite a while. There are numerous trail-like formations that can throw you off course. I found it necessary to cross over to the right side a bit prematurely and ended up climbing rocks a lot more than I anticipated. The best course of action would be to cross from left to right at about 9900 feet (per my altimeter which could be off some), probably better than midway up the gully.
The climb does get easier once you get higher up the gully. It is a relief to reach the meadow on top of the Sphinx just before the final ascent. There was some snow on the top, but crossing it was not necessary to reach the summit.
There is some minor scrambling to reach the summit ridge, but compared to the gully, it is not bad at all. From the top, you can see the Spanish Peaks region, the Madison Range, the Gallatin Range, Lone Mountain, and lots more! Oh and there is a 2000' drop-off just over that summit ridge, wow!
DownwardThe trail that follows the gully is much easier to find on the way down. That's what made the way down easier for me, I was able to stay on trail. It is a class 3 descent until the small groves are reached again on the saddle ridge. Once I reached the ridge, I changed over to running shoes and ran a good 2 miles before reaching the grand meadow, when I decided to walk again.
This was a great climb. There is a definite sense of accomplishment that comes along with successfully summitting the Sphinx, especially when looking back at the Sphinx from the county road. It is quite the impressive mountain.
I was sure glad I had a little bit of rock climbing experience during the gully ascent. It just helped to understand hand holds and how to use them. I did this climb in 7 hours from TH to TH, but I was also hiking solo, ran some, and did not take much for breaks other than to change my shoes/socks. I'd suspect the norm is closer to 8 hours.