7/23/2013
This is a surface of some kind, opened on 7/20/2013.
Locus 18 is next to locus 16, also likely above locus 17, but is a much lighter color than locus 16. It is still possible that this is the same surface as locus 16.
top elevation: 2295.005
bottom elevations
E: 2294.98
W: 2294.92