The following background material is not needed to find the cache. (September 5, 2023: Several links are no longer functioning as they used to.)
(September 5, 2023: This link is broken.)This cutting had puzzled me since I first found it in 1994; I recently concluded that it was part of an old railway used to haul logs and timber from Glenbrook. (In the above linked article, in the photo, the two men are almost at GZ. Note the rock beyond (just left of) the man in the bright blue jacket. I think that may be the rock beneath which the cache is hidden. Correction as of September 5, 2023: The above link has been replaced with one that leads to a different location on the website http://www.truckeedonnerrailroadsociety.com. I regret that I no longer know where to find the photo.)
The Carson and Tahoe Lumber and Fluming Company was organized in Nevada in 1873. It was probably the largest and most extensive lumber operation serving the mines of the Comstock. Holdings included timber lands around Lake Tahoe in Nevada and California.
The size of the operation is conveyed by this article.
Here, in Myron Angel's 1881 book, History of Nevada, on page 286 I found more information about this particular railway.
Here is a photo (September 5, 2023: This link is broken.)looking down Slaughterhouse Canyon towards Glenbrook. I believe the photo depicts the view from above present-day Highway 28; I think Highway 28 now follows the route of the straight line in the middle foreground which a photo caption elsewhere on the web refers to as a flume and a pipe. If you use the zoom function with this photo you can locate six men within the photo.
Here is a photo, dated 1877, that I believe shows the railway just east of the point at which the cutting meets the main track, at, say, about N 39 07.757, W 119 56.148. In fact, if you can locate yourself at those coordinates and look at the hillside between the tracks to the east you will be able to see two prominent rocks in the photo, the light-colored slab that seems to drape the hillside, and the distinctly colored somewhat dome-shaped rock (darker, with a lighter vertical marking) beyond it; I was struck by how the surface of that rock retains now the same markings it had then. (And yes, actually you will have to move eastward from these coordinates, past a large tree in order to see those two rocks clearly.)
Here is a photo, dated 1868-1873, that shows the railway terminus in Glenbrook. Zooming in on this and the preceding photo reveals significant detail.
Finally, here is a link to a (September 5, 2023: This link is broken.) free online topographic map source . If you follow the link, enter "Slaughterhouse Canyon, Glenbrook, NV, United States" in the search box. That search will lead you to a map that depicts the terrain followed by the switchback route of the now vanished railway. The old railway route is now depicted in four different ways: as a vehicle track (a double dashed black line leading up through Slaughterhouse Canyon), as a trail (a dashed black line ascending the east and then north slopes out of the canyon), as a dirt road (a dashed grey and white line ascending further, eastward, along the north slope ), and as the current highway 28 (a dashed red and white line on the map which took the trains south to Spooner Summit and connected with the flume to Carson City).
In addition to the information about this small railway, I enjoyed a brief overview article that puts this location in geographical and historical context from the perspective of timber harvesting in the last quarter of the 1800s. Readers already familiar with the broader context of the development of the Comstock may drop to the end of page 7 for the particulars of relevance to the location of this cache. The article includes some fine photos, and a list of sources.
Enjoy the cache.