235930  Excavation Contractors 

This U.S. industry comprises establishments primarily engaged in
preparing land for building construction. Activities performed by these
establishments are drilling shafts, foundation digging, foundation
drilling, and grading. The excavation work performed includes new work,
additions, alterations, and repairs. 

The data published with NAICS code 235930 include the following SIC industry:

1794 Excavation work special trade contractors