Sharp Top and Diablo Peak
Diablo Rim is the large heavily faulted uplift between the Lake Abert and Summer Lake Basins. Segmenting into many narrow longitudinal sections, this rim has a number of distinctive highpoints. Of these Sharp Top is the highest summit on the south end of the Diablo Rim and the most accessible to drive within hiking distance of. Roughly 10 miles further north is the uplifts namesake highpoint, Diablo Peak at 6147 feet. Diablo Peak has more elevation and greater relief, but is more difficult to access due to road conditions. The absolute highest point in the immediate region of Diablo Rim is Coglan Buttes at 6209 feet overlooking the southern Summer Lake Basin. In absolute elevation these are not big summits, but in terms of relief expect to see thousands of feet of elevation change in less than a mile.
The Diablo Uplift is an arid region of sagebrush, bunchgrasses and very little else. There are no trees whatsoever although they are visible on distant rimtops to the east and west. While wildlife may seem scarce, deer and antelope frequent this region, as do thousands of migratory and seasonal birds that are attracted to the large lake basins below. Its quite common to see Ferruginous Hawks and Golden Eagles soaring above the rimtops, and mule deer roaming the flatlands below. Visible from the summit of Sharp Top is the Steens Mountain crest in the east, and all Three Sisters and Bachelor can be seen to the west.
Red Tape - When to Hike
The most advisable time to hike in this area is certainly the winter season for a couple of great big reasons. Primarily Sharp Top is at a low enough elevation for rattlesnakes to be a very real concern. The summit is comprised of a jumble of basaltic boulders with signs of dead rodents very prevalent, I personally wouldnt summit this peak any later than March for this reason. Also, there are no trails, so ticks would also be a serious seasonal concern. Additionally finding water outside of the winter season will be almost impossible. There are a few waterholes scratched into the landscape for cattle, but expect to find them either dry or surrounded by cows. With so little snowpack roads are typically dry and quite driveable year round.
Finally a lot of this region belongs to the ZX ranch, and you will be hiking on open range possibly encountering cattle. Optimally winter is the best time to do this hike and cattle will still be down in the Summer Lake Basin so this wont be an issue.
Sharp Top Summit
The most reasonable access for Sharp Top is the Red House Road on the north end of Paisley. This road is paved the first four miles and then transitions to gravel. At the end of the pavement is a "Y", here you will veer left toward Sand Hollow, the large canyon ahead of you. The road up Sand Hollow is in relatively good condition, reasonably wide and mildly washboarded. Follow the gravel road up Sand Hollow approximately 6 miles to a pass where you will see a rough dirt 4x4 road descending down into the basin along the east side of Diablo Rim. This road eventually leads to Jackings Hole, Murphys Lake (seasonal), and the steep east face of Diablo Peak. Follow this road 3 miles passing the Sprinkle Waterhole to a draw on the west side of the road. Park here, and begin west up the draw. Once you reach the rim crest above, you will see Sharp Top roughly a mile and a half in the distance (as seen in the picture below). Total roundtrip walking distance is nearly 4 miles with just under 1000 feet of elevation gain.
Diablo Peak can be accessed from the east or west. From the east, merely continue past the route for Sharp Top descending deeper in the Diablo Basin. Its an additional 12 miles on this rough road to the eastern base of the mountain. From there its a steep 1500 foot climb in roughly one mile to the summit. A more reasonable approach is given in the book Oregon Desert Guide. That is the western route that begins north of Summer Lake in the dry marshlands and travels about 11 miles roundtrip with 2000 feet of elevation gain. Seen below, Diablo Peak from across the North Summer Lake Basin.
There are no campgrounds in this region once you travel away from Summer Lake. Although hundreds of miles from anywhere, Sharp Top is a dayhike at worst, and Diablo Peak would be a long dayhike. A lot of this region is BLM land, so if a multi-day trip is made to the Diablo Rim region, camping could theoretically be done anywhere.