Three Creeks Summer Kickoff Party Kick off Summer with live music, food trucks, yard games, bikes and brews at the Three Creeks Brewing Co. production brewery on Saturday, May 28th from 4-8pm. All ages are welcome to join in celebrating the beginning of the Summer event season and the return of the The Sisters Stampede, the largest mountain bike race in Oregon, held on Sunday May 29th right here in Sisters.