I took an easier route than shown on the map on the summit page. Starting from Geyser Pass, I drove north on the 4WD road (shown as 0243 on the USGS topo) which ended at a nice campsite. From there, it's a short walk north through the trees where there are faint trails and a few fallen trees to step over. Once out of the trees there's a decent trail (either a game/cow or use trail, not constructed or maintained) all the way to the saddle between Haystack Mountain and Burro Ridge. The climb from the saddle, up through the talus, to the summit of Haystack Mountain wasn't bad at all. The talus was larger and fairly well-consolidated, and while the going was tedious, I didn't have any major spills going up or down.