About 10 years ago, on one of our Whitney dayhikes, we saw a trail maintenance crew working on the upper part of the 97 switchbacks. They were using 6 foot long pry bars to move large rocks. I don't know if they were forest service employees, contractors, or volunteers. We never had any trouble going up that difficult section at night by headlamp. Strangely, coming down in daylight was different. There are spots where you have to look ahead dozens of feet to see where the trail continues. Then, all you see are scuff marks on the granite. Once we were sitting on a large rock by the creek just past Outpost Camp about 3AM drawing water. A group of six hikers came by descending. They had started the day before on the Mountaineer's Route. They complained about how difficult the section above Mirror Lake was. They said they lost the trail several times.