Mayfly Engineering + Design Share: Civil Engineering Mayfly Engineering + Design Visit Website 3715 California Ave SW, Suite 108A Seattle, Washington 98136-1011 (206) 935-5356 About Map About Founded in 2006, Mayfly is a civil engineering company that specializes in the design and planning of projects that are sensitive to both their social and natural environments. What's Nearby? Distance: 5 10 15 20 25 50 mi.
