The Ride for Missing Children is set for Friday, June 1st. The day will come and go without you, though, if you do not register to participate. New riders must register by February 28th. You can do so here.
The local chapter of the National Center for Missing and Exploited Children creates and distributes posters of missing children nationally and into Mexico and Canada. The ride helps pay for those posters.

The ride is personal. The hundreds of cyclists, who take part, wear a pin of a missing child that they are riding for that day.
Organizers say now is the time to start training and making sure your bike is in working order.