The route for Mount Valois is sequenced with Aztec Mountain. Elevation gain and mileage are measured from the summit of Aztec to Valois. Our suggested climb begins from a base camp at the Durango City Reservoir #1 which you have backpacked into and set up a base camp. The Aztec-Valois combination makes for a moderately long day hike of nearly 11 miles round trip from the suggested base camp.
From the summit of Aztec Mountain you can walk east along the ridge crest to a saddle between Aztec and Pt.13,190. This is mostly Class 2. "Furthermore" on LoJ makes mention of a few brief 3rd class scrambles. Our notes did not record such. At the saddle, you could continue along the ridge crest and follow it to Pt.13,190, then south to Bullion Mtn., SE to Florida Mtn., then SE to Mount Valois. This long ridge hike would not net any more ranked 13ers. It does not appear too difficult except the Bullion Mtn. stretch which appears to have some difficulties. If the weather permits, you may want to consider this route to Mount Valois. The day we hiked these peaks, by the time were heading off of Aztec, we were dodging lightening bolts, so it seemed prudent to take a safer route over to Valois that kept us off exposed ridges.
So, from the Aztec-Pt.13,190 saddle, drop south on scree at first that turns to tundra lower down. Drop into the basin west of and below Bullion Mtn. to about 12,400 ft. Turn SE, then east toward Trimble Pass, regaining nearly 600 hundred feet in elevation over mostly tundra terrain with some rocky outcrops and rubble thrown in. Follow similar terrain down to Lillie Lake, below Florida Mountain, losing about 300 feet in elevation. At Trimble Pass, you'll intersect a trail that leads north into Vallecito Basin at the head of Johnson Creek. This trail will lead for a short distance down to Lillie Lake, but you'll have to depart it to reach the lake.
From Lillie Lake, begin hiking up a low ridge that drops down to Lillie Lake, descending off the north ridge of Valois. This ridge quickly becomes very rocky. Head for a prominent notch on the north ridge. Contour south to gain the north ridge at whatever point footing allows you. Gaining this notch and following the ridge south until you hit the wide, flat summit plateau is a frustrating Class 2+ scramble across a multitude of boulders with very insecure footing. This will be the only really difficult part of the day. If the rocks are wet from rain, they will be treacherous. Once on the summit plateau, it's a stroll to the high point which is located near the beginning of the east ridge of Valois. On a clearer day, you'll have good views toward Amherst and Organ, and the impressive peaks above Johnson Creek tot he north.
After visiting the summit, the most direct and easiest way back to camp is to walk down the mostly tundra ridge a short ways to the south toward a saddle between Valois and Pt.12,954. Watch for a break in the cliffs along the west side of the ridge and when you see a good opportunity to head west and down, do so. Once down through the upper rocks and cliffs, it will be mostly a tundra descent back into "Crystal Valley." Once in the valley bottom, head south to Lake Marie, pick up the trail you followed in the morning and follow it back down to the base camp at City Reservoir #1.
Links to other information, routes & trip reports for this peak that may be helpful.