(Estacada, OR)  --  A 12-year-old boy is being hospitalized after a skateboarding accident at Milo McIver State Park in Estacada.  Oregon State Police say the boy crashed as he was heading downhill on the park's entrance road Saturday.  Police say the boy was not wearing a helmet, even though Oregon law requires kids age 15 and under to wear them while skateboarding or riding other wheeled vehicles.  The boy is said to be improving and may be released from the hospital later this week.