I was finally able to talk with Orange County parks and rec today, they are open to putting up a large sign/billboard at Booster park but said it is very windy there. They also said they are always in need of more benches and we could do some 'display' benches. They also agreed to put up laminated posters all over for us but warned that their parks don't have alot of walk-ability and that we may have better exposure if we do an in-town park.

Here is a digital option:

43" Multimedia Advertising Kiosk | Wifi & Bluetooth Enabled (displays2go.com)

This could be moved to different locations/counties for similar campaigns.