The World Naked Bike Ride in Portland is one of the largest editions of the international event, partly because it meets the city's quirk factor.
The ride came at the height of a short heat wave in the Willamette Valley. An, ahem, breezy ride was quite welcome as temperatures climbed into the upper 90s.
Thousands swarmed Fernhill Park in Northeast Portland to revel in their nakedness before the ride.
They then cascaded through the northeast quadrant to a picturesque Burnside Bridge, the westbound lanes of which became the site of shared euphoria.
The route isn't revealed prior to the event, so ending on Burnside was a pleasant surprise for many.
It's hard to think of something more Portland than a throng of naked bicyclists dancing in the glow of the city's famous White Stag sign.
A skateboarding sailor joins the ride.
Bradley W. Parks
/One of those days.
Bradley W. Parks
/A group of gold-covered gladiators quickly became the life of the party prior to the ride.
Bradley W. Parks
/A man named John works on his ride: Pegasus.
Bradley W. Parks
/A couple of friends swing among thousands of fellow nude participants. Mount Scott Park provides 11 acres recreational facilities among numerous trees.
Shirley Chan
/Nude riders wait to get on the road at the 13th Annual World Naked Bike Ride in Mount Scott Park in Portland, Ore. on Saturday, June 25, 2016.
Shirley Chan
/Volunteers of the World Naked Bike Ride promote bike safety and the recommended dress code by wearing helmets. Portland Police Bureau said wearing helmets and shoes should be the "bare minimum" in a statement released prior to the event.
Shirley Chan
/A man sits in the nude and waits for the ride to begin. The World Naked Bike Ride is an all-ages for cyclists of all skill level.
Shirley Chan
/Participants paint slogans and messages as a form of advocacy on their naked bodies.
Shirley Chan
/Participants check their bicycles before taking off. The World Naked Bike Ride is a protest against fossil fuel dependency, for bike safety and for body positivity.
Shirley Chan
/Participants use their bodies as a canvas to protest for why they ride. Reducing fossil fuel dependency is one of the many reasons people ride.
Shirley Chan
/Ken Marshall, left, and David Smith, right, traveled all the way from Los Angeles. Tens of thousands of people participate in Portland's event in comparison to Los Angeles' nearly 500 participants.
Shirley Chan
/Spectators line up on the streets adjacent to Southeast 74th and Southeast Knight Street cheering on and taking photos of nude riders.
Shirley Chan
/Nude riders cruise down the streets of Southeast Portland illuminated by police car lights at every major intersection.
Shirley Chan
/Participants ride into the night on Woodstock Boulevard with high energy. The route started at Mount Scott Park, traveled through Southeast Portland and ended at Sellwood Park.
Shirley Chan
/Never change, guy.
Bradley W. Parks
/A sea of butts.
Bradley W. Parks
/Cyclists zoom by the corner of Fremont and 42nd.
Bradley W. Parks
/Copyright 2017 Oregon Public Broadcasting