Timed / looped events are perhaps the best possible entry point to ultra running, so I'm happy to present the first (of hopefully several) put on by Run Pacifica.
This is a 10-hour event, going from 8am to 6pm.
It's at Lake Marie in the Umpqua Lighthouse State Park, just south of Winchester Bay. The loop is one mile, flat overall with some very gentle rolling and a couple of roots and rocks to keep you interested.
It's free, so bring your own food -- your call whether you want to share with fellow runners or just have a stash for yourself (really, either option is fine).