This is in quick answer to Stephan and Ron's queries: The metal piece is part of CA-SBA-3725H, the NTU mine. The site was recorded during a survey for the current oil field development in 2003 by a different company, under the California Environmental Quality Act (CEQA) regulatory framework. The site was recommended as eligible to the California Register of Historic Resources. Mitigation measures included avoidance and HABS/HAER photographic documentation of above-ground structures (preferred), and monitoring and a program of testing for subsurface deposits for locations where ground disturbance could not be avoided. Development of the oil field is moving forward, and we are now in the process of testing and monitoring across the project area (a number of prehistoric sites in the project area also require testing). Disturbance to the site with the metal piece is minimal. The oil company has made a great deal of effort to be as minimally damaging as possible to the area as a whole, including using previously established roads rather than blading new ones. The metal piece happens to lie next to one of these roads in a small narrow valley. There isn't anywhere else to put a road through that area without affecting other resources (including some NTU-related foundations and a building) and causing a great deal more disturbance. The original intention was to avoid the piece altogether and leave it in place as part of the historic mining landscape. It has become apparent, however, with the movement of the oil traffic and all of the rain that California has been getting recently, that avoidance may end very abruptly if a truck slides in the mud. Protective fencing won't help very much in that case. So, we are trying to assess alternatives. Again, thank you for all of the suggestions and conversation. It is very helpful. best, Marcy