CRM situations do bring additional criteria in deciding aspects of
mitigation.  Certainly ascribing considerable funds and time to a given
archaeological site is  a gamble: much may be invested with little in
knowledge return: 'negative evidence' notwithstanding.  I am reminded of
an intense excavation of an ancient Maya site in Belize some years ago:
large crew, large excavation area, no artifacts of significance
recovered.  However, a colleague visited the site  during the field
season and found the one wonderful artifact to represent the season's
efforts: a small jade carving.  However, it was not from the excavation,
but from along the edge of the road nearby, which had been  recently
built with fill from bulldozed structures at the same site.

Larry Buhr
Dept. of Anthropology
Univ. of Nevada, Reno