Westercon 67, held this past July 4th weekend in Salt Lake City, drew 636 attending members.
Notes added to the Westercon.org history page by Kevin Standlee (using figures provided by Jordan Brown, Westercon 67 Registrar) show there were 98 no-shows.
Of all present, 199 purchased memberships At-the-Door.
Standlee also explained that on site were another 220 ticketholders from FantasyCon, an independent event held simultaneously across the street from Westercon, who attended Westercon under a joint-admission policy between the two events. “An exact count was not possible because of the joint admission; 220 is the count of those FantasyCon attendees who registered their joint attendance with the Westercon registration desk.”