The Lower slopes of Mount Rose, and most of the long, lower ridge of the Carson Range to the north, are draped with Tertiary volcanic rocks. The top of Mount Rose is also capped with a layer of Tertiary volcanic rocks. These rocks weather to dark gray and brown, causing the peak to appear darker than other nearby peaks in the Carson Range.
Several hiking trails lead to the saddle-shaped peak of Mt. Rose, which can be reached from Galena Creek Park via the Jones Whites Loop Trail (JWLT) and Church's Pond, via the Thomas Creek Trail further north and from locations along the Mt. Rose Highway (State Route 431). The climbing trips starting at the Mt. Rose Highway have been described in detail as Trip 9 “Southeast Ridge of Mt Rose” (5.4 miles, out-and-back) and Trip 10 “Mt. Rose” (9.8 miles, out-and-back) in Mike White's Reno-Tahoe hiking guide . Trip 10 is by far the most popular option since it includes an easy hike along the Tahoe Rim Trail (TRT): a semi-loop around the northeast base of Tamarack Peak. This trail section through open hemlock and pine forest takes you to a seasonal waterfall. From there, the trail continues through lush meadows over tributaries of Galena Creek to a marked junction, from where the “real ascend” onto Mt. Rose begins. The Mt. Rose Trail is well marked—and typically well travelled. Don't expect to be alone on the summit.
With an elevation of 10,778 feet (TRT handout “Brockway Summit to Mt. Rose Trailhead”), the summit offers a panoramic 360-degree view with the Virginia Range in the east, Lassen Peak in the north (on a very clear day), Truckee, Donner Lake and Castle Peak in the west and the Lake Tahoe scenery in the southwest. On my last visit in June this year, I found a nicely assembled rock sculpture, shown in the right-side picture above with the snowy slopes and peaks of the Desolation Wilderness in the background. Unless some tired hiker is sitting on that particular summit rock, you should be able to spot the U.S. Coast & Geodetic Survey Reference Mark fixed thereon (left-side picture above).
References and more to explore
 J. V. Tingley, K. A. Pizarro, C. Ross, B. W. Purkey and L. J. Garside: Geologic and Natural History Tours in the Reno Area. Expanded Edition (Nevada Bureau of Mines and Geology Special Publication 19), University of Nevada, Reno, 2005; page 29.
 Mike White: Afoot & Afield. Wilderness Press, Berkeley, California, 2nd printing 2008; pp. 246-249.