This ride was in conjunction with something called 'Hempfest', just a shame all the riders were male......except the lady below! There are some more images on Flikr, but these are the best so far.
There was also a WNBR event in St Louis, but despite in being dark and having loads of young lady riders, almost everybody rode in their underwear
. A few women rode nude or almost nude, but they were older ladies. Do a search of Flikr for the pics, there are loads of them.