The Park People produce a book every five years that lists over 250 trees in Harris County, it's an educational tool. The profits for this book are used to restore and preserve natural areas and trails in the Houston area.
The Tree Registry was published to celebrate and encourage the preservation of Houston areas fine old trees. The registry is a record of the largest trees of all species that are alive or naturalized in Harris County. Tall Trees is the 4th edition of the Tree Registry.