From the car park coordinates, walk NW along an old road that may have a locked gate and marked as Private Property. We saw no human activity beyond here, so you decide how you want to proceed. If concerned about being a violator, hike up the mountain side slope no more than about 200 feet in elevation and a game trail should appear that you may continue following NW, then north to Thorne Lake. If you stay on the road, after about 1/3rd mile, a faint trail turns off the road anyhow and leads up to Thorne Lake. Beyond the lake, continue on an old roadbed/trail into Middle basin, below the Montana Mine. From here, you could try gaining the sharp and narrow south ridge of T.5, but the appearance of numerous rocky difficulties along that ridge prompted us to try another route. So we aimed for a large couloir that drops to the Montana Mine from just east of the T.5 summit. As you head north above the mine, you'll immediately encounter some steep scrambling up a rocky slope to another bench level at just below 12,600 ft.
From this upper bench, head into the couloir. The bottom few hundred feet will be mostly medium-sized, loose rocks that are reasonably stable. The higher you ascend however, the more the rocks give way to steeper gravel and sand. Footing becomes tenuous. About 400 feet up, it becomes so steep, that to keep forward progress going, we found it useful to plunge our ice axes into the sand/gravel in order to pull ourselves up. Only the last 100 vertical feet offer any relief in steepness. Then it becomes a quick and easy stroll over small scree to the summit. The only good news regarding this route is if you descend the same way, you can scree/ski your way down quickly. If taking this route, you may want to consider dropping back down into Middle Basin and crossing east over to climb both Chicago Peak and UN13,095. be warned though, most all of that route will be on cruddy, loose rock.