This guide is based on a Sage article by Reinhold Janson. It combines Jurassic Peak (aka Haiwee Ridge), Scattered Bone Peak and Cactus Flat Peak.
Topo Map: Haiwee Reservoir 15
Trip Stats: 5 mi. r.t., 1700' , Class 2-3
These peaks are east of the Haiwee Reservoirs, outside of the Coso Wilderness proper. Clearly viewed from Hwy 395, they can be done as a nice loop from either the east or west. To get to the eastern starting point, leave Hwy 395 in the township blip of Grant and take the signed Cactus Flat Road east (across from the Olancha Fire Station). Paved at first, it turns to excellent dirt past the ranches, as it crosses inlet of the North Haiwee Reservoir. Continue southeast on this excellent dirt road until you reach Cactus Flat (4500'). At the first prominent junction on the Flat, keep right and go south about 2.5 miles, then turn right again on a fainter fork and go south another 2 miles to park (5000'). If heading downhill, you have gone too far. 2WD should be able to get to this roadhead.
Immediately to the northwest is the saddle between Jurassic and Scattered Bone Pks. Head for it, picking up a faint mining road en route. From the saddle, climb north on the ridge to the summit boulders of Jurassic Pk. Some scrambling is required. Retrace your way to the saddle and continue south up the easy ridge to Scattered Bone Pk. Finally, head southwest along the ridge to Cactus Flat Pk. Return east over or around Scattered Bone Pk to the parking area. There are primitive registers on the peaks (and a scattered bone or two).
The alternative western approach features a shorter drive and interesting niining detritus. Drive east less than a mile from Hwy 395 on a signed road (Haiwee Reservoir Rd?). This is south of the Cactus Flat Rd. Park at the road's end lot west of South Halwee Reservoir. Cross the dam spillway (3759') and trace an old mining road, not shown on the topo, for 2 to 3 miles to reach the aforementioned saddle between Jurassic and Scattered Bone Pks. Pass abandoned mining shafts and equipment. Ascend the peaks as described. Return the same way, or for a loop descend the northwest slope from Cactus Flat Pk to the reservoir. In the latter case, pass through a white talc outcropping and by mining artifacts en route.
The Coso Range Wilderness was created by the California Desert Protection Act of 1994. It is situated at the southeast comer of Owens Valley, north and west of the China Lake Naval Weapons Center in Inyo County. This tranquil region is rarely visited. Encountering others in this wilderness is unusual. Apart from the mining roads that skirt its fringes, it remains largely untouched by man. Andy Smatko, Gordon MacLeod, and Barbara Lilley are among the few names in the summit registers.