I heard of another great National Public Lands Day Event that I wanted to share. Whole Earth Provisions is hosting a clean up the Mission Parks Event from 9-12 September 26th. Then there will be an after party at the store in the Quarry Market with small prizes for the participants and a screening of Ken Burns PBS documentary National Parks: America's Best Idea. Sounds like a good time to be had by all.
There is a similar event in Austin at McKinney Falls State Park.