Found a slideshow of photos from May Day 2002, but not yet exactly what I am looking for. I also need to sort out the exact year the westside event happened.
Update: The year is 2001, found this handy summary in the emergency management archives-
On May 1 approximately 300 protesters assembled near the south entrance of Black Lake and Harrison Avenue in Olympia Washington as part of the May Day Protest Activity. The protesters began moving toward downtown Olympia and the 5th Street Bridge around 4:35 PM but returned to a vacant lot on Black Lake Boulevard without major incident.