What usually happens to preserve this kind of site, and does it interfere with the use of the facility for the military purposes?
Unless the site it determined to be incredibly significant it doesn't stop any project. Here is a very basic synopsis of the type of work we do in a situation like this....
Basic Cultural Resource Management studies are performed in phases.
Phase 1 is a presence or absence survey (usually shovel testing at predetermined intervals) to determine if there are any cultural features within the proposed project area. If nothing of note is found, the project goes forward immediately, if resources are found that are deemed worth of further study the next step is undertaken which is...
Phase 2 is a limited excavation to determine the existence of intact subsurface features. During this phase small excavation units are opened in the areas of heaviest cultural activity. The purpose is to determine whether any significant archaeological features remain intact within the project area. If not, then the project moves forward immediately, if so then the next phase is undertaken which is.....
Phase 3 is a proper excavation of a portion of the significant cultural resource. Usually excavation units are opened that cover from 5 to 80% of a site (depending on its size). Usually the average is 10-20%. The purpose of this phase is to record as much available date about the cultural resource to determine it's signifigance before either preservation or destruction. Once this phase is complete, 99 times out of 100 the project goes forward and the site is destroyed. On very rare occassions, the area is determined too important to destroy (burial grounds etc.) and the project must either be cancelled or more often, redesigned to lessen or eliminate impact on the archaeological resource.
During all phases, the work performed is scrutinized by pertinent local, state and Federal officials (if applicable).