(Portland, OR)  --  Thousands of people will ride bicycles naked through the streets of Portland tomorrow night.  The 2017 World Naked Bike Ride is a protest against dependency on fossil fuels, though riders in the annual event often promote their own causes using body paint.  Participants will meet up at Fernhill Park at 8 p.m. Saturday.  Organizers say the route of the seven-mile bike ride will not be disclosed until the day of the event, to minimize the presence of gawkers.  About ten-thousand people participated in last year's Naked Bike Ride.