DCHP-1 Online
bottom ((v.)) Placer Mining 
v. excavate down to bed-rock (def. 1).
See also: bed-rock (def. 1)
- 1869 It is strange, with the well-known proximity of rich quartz beds in Snowshoe mountain, that Snowshoe creek has never been bottomed.
- 1900 There are also many valleys where, though the bed of the existing stream has proved rich in gold, the old channel has never been "bottomed."
- 1869 It is strange, with the well-known proximity of rich quartz beds in Snowshoe mountain, that Snowshoe creek has never been bottomed.