In 125 years, Sun Prairie has transformed – and Sun Prairie’s fire department right along with it. The boundaries have expanded, changing from a rural town to a bustling suburb. The population has exploded. Businesses have closed, or opened and grown. But through it all, one piece has been a constant: the steadfast Sun Prairie Volunteer Fire Department (SPVFD). Firefighter Matt Scovill said the department’s 125th anniversary is monumental. “I think it’s a major accomplishment to be able to continue in a community that has grown as much as Sun Prairie,” he said. Scovill is co-chair of the department’s quasquicentennial celebration on Sunday, Sept. 18. It begins with a Main Street parade at noon, followed by a short ceremony and an auto show with fire trucks, cars, trucks and motorcycles. Later, the Adam Bartels Band and Wheelhouse will perform.