Rock Creek is on the west side of the Desatoya Range, and the road to the base of the climb is a dirt trail off of US Hwy 50. 4WD is not required, but clearance is. The turnoff is approximately 120mi east of Reno, NV, and 60mi east of Fallon, NV. If traveling east on US 50 from Fallon, drive past Middlegate station and look for a dirt road on the right (east) side of the highway 11.1mi from Middlegate Junction/Station. There are several dirt roads in the valley, so make sure you take the correct one. The road to Rock Creek is not maintained or graded in any way, and happens to be exactly opposite a similar turnoff on the left (west)side of the highway. Proceed through a cattle gate (close it behind you), and approximately 3.5mi up the alluvial fan to the end near the mouth of Rock Creek.
The route starts on the north side of Rock Creek, and proceeds up a series of ridges to Desatoya North Twin. From the end of the dirt road, start contouring NE up the slope towards the ridge on the north side of Rock Creek. Once on the ridgeline, follow it up through a Pinion/Juniper forest, negotiating rock outcrops along the way. If any large obstacles are encountered, stay on the left (N) side of the ridge as the south side is quite steep.
After the first mile, large, old mountain mahogany begins to inhabit the hillsides. After an open saddle area at the 7800' level, a short steep hillside blocks the way with vegetation and rock outcrops. Here, either bear left on the slope, or 3rd-class it near the ridgeline. Once this obstacle is past, continue up to a rocky point, bearing left (N) to avoid a whole hillside of small mahogany.
From this rocky point onwards, you are above treeline. Proceed east across an open saddle and up a short gentle slope to a small knoll at the 9200' level. From here, the peaks are obvious, with the North Twin being only 0.75mi away. Climb the final slope to the North Twin, and then down and across the saddle to the high point on South Twin.
Reverse the route for the fastest decsent.
During the summertime, bring enough water for the whole hike, and then some --- evaporation rates are high, and humidity is low. A good hat and light boots are needed as well. The brush is not high enough to require gaiters, so leave them at home.
During the wintertime or mid-season, expect some snow accumulations on the north slopes and drifts on the crest. The route may be seen from the valley before driving into the campground, so check out the north slope of the peak on the way in to see if crampons might be needed.