Two people needed to be extricated from their vehicle after it left Valley Road south of Oconomowoc early Saturday morning.   According to the Western Lakes Fire District, the vehicle left Valley Road just west of Golden Lake Road around midnight.   EMS and fire crews took about 15 minutes to get the two injured persons out of the car.  They were then taken to a local trauma center for treatment of their injuries.  No other vehicles were involved in the accident.  The Oconomowoc Police Department has no further information about the accident.