This is probably the shortest and most direct of the three SP routes for this peak if you have and use 4wd. Depending on the route chosen, this can be a strictly Class 2 ridge walk or, taken more directly, a mixed hike and scramble that can get into Class 4 sections on rotten rock. As it is all above timberline, the entire route is highly scenic.
To enjoy all that’s great about Ruby Mountain but minimize the approach, you will need a 4WD vehicle. If, though, that is not an option, you can still get close enough to the peak to make it worth doing.
From U.S. 6 at the eastern end of Keystone, take the signed road to Montezuma. This road is easy to find if one is traveling eastbound, but there is no direct access to it for westbound travelers, who will have to watch for the road and then make a U-turn to get to it.
At 4.3 miles from U.S. 6, look for a parking area on the left. Beside it, a dirt road heads east. This is the Peru Creek Road, and it is passable to passenger cars for approximately 5 miles, after which the road becomes markedly steeper and rougher, soon requiring high clearance and 4WD if one is to continue on. The Peru Creek Road becomes a very scenic drive after about 3 miles, passing many relics of the area’s mining heyday as it climbs through an open, verdant alpine basin, through which runs a chalk-white stream colored by calcium carried by the water. Peru Creek and some of its tributaries often strongly resemble the glacial streams that one finds in the Canadian Rockies.
There is a good-sized parking area on the left side of the road at 4.7 miles (11,100’), and this is a good spot to park a passenger car (starting from here and following the route described on this page will add about 3 miles RT and over 1000’ to your climb). There is a gate (open in the summer) at 4.8 miles, and at 5 miles is the trailhead for Argentine Pass (11,300’-- the TH, not the pass), which also has some parking and is about as far up the road as one should go in a passenger car.
But if you have 4WD and can use it, you can continue on at least 1.2 more miles, where the road forks. Take the left fork (the right climbs steeply to some more mine ruins and is used by hikers heading for Grays Peak) for another tenth of a mile to a small de facto parking area by a willow-encircled pond and just before a crossing of a narrow stream. The elevation here is approximately 12,100’. The road continues beyond this point, leading about another half a mile to a 12,200’ lake (and past that to more mine ruins) at the base of Ruby Mountain’s northern end, but following the road further requires a sketchy water crossing. The road crosses just above the outlet of the pond, which is rocky and shallow enough in late summer, but the outlet drops sharply into a boggy spot, and one slip of the tires or mistake in wheel placement could mean you are mired. It’s easier, then, to park at the 6.1-mile mark and finish the approach from there.
If you start from the parking area described in the preceding section, you are looking at 3-5 miles RT and around 1200' of elevation gain. If you start from someplace else, adjust distance and elevation-gain estimates accordingly.
Consider one of three options: contouring around the mountain to attain and follow the ridge itself (Class 2), hiking up talus to the prominent cliff bands on the northern side of the ridge (Class 3-4), or the long, steep, sandy-colored scree slope to the right of the cliffs (Class 2). I went through the highest and furthest-right cliffs, and details follow. I used this route to reach the crest of the ridge, after which I followed the Class 2 ridge to the false summit at Ruby’s northern end and then finished with an easy hike to the true summit.
As the 4WD road approaches the 12,200’ lake at the head of Falls Gulch below the Ruby-Grays ridge, a rugged rock face, just right of which is a steep, yellowish talus gully, appears. Ascend the talus and scree to these rocks, and then let the fun begin. With very careful route-finding, one might be able to keep the climbing here at Class 3, but the mountain just seems to funnel you into very steep, tight gullies with lots of loose rock and solid rock bands that nevertheless require tricky moves. At times, you may find yourself surprisingly and uncomfortably exposed and surrounded by bad rock; it’s not the rock of the Elks or the kind of exposure that makes for falls of hundreds of feet, but the rock and exposure are bad enough to kill you, so respect this mountain.
The climbing ends on airy slabs after only about 150', but it's worth it considering that most peaks in this area of the Front Range offer little other than walk-ups unless one gets quite creative and daring. It's then a Class 2 trek up to the false summit that from below looked as though it just had to be the true one. Near that false summit is also where the true summit comes into view for the first time along this route (the true summit is easily seen from lower in Horseshoe Basin but not from the upper parking area or the early parts of the climb). Along the ascent there are spectacular views of upper Horseshoe Basin and the Continental Divide, and there is also a fine view of the 12,838’ notch dividing Ruby from Grays, as well as the exciting-looking south ridge of Grays (easily Class 3, likely harder in spots even by the easiest way, assuming one follows the ridge itself).
From the false summit, you also finally get your first glimpses of what lies on the other side of Ruby Peak; directly below is upper Ruby Gulch, and the vista in the distance stretches from the Mosquito Range to the Gore Range, with the Sawatch on the far horizon. Pikes Peak is even visible far to the south, and you can make out the Sangre De Cristos on very clear days.
The hike to the true summit is easy and mostly flat, involving very little elevation change even on the final “push,” if it can really be called that. This final hike may take fewer than 10 minutes to do.