Our nonprofit has a fairly extensive list of trees we catalog and maintain on both public and private land. Here's the public trees: https://heritageapplecorps.org/index.php/All_Trees

But our mission is really heritage trees, which we loosely define as pre-WWII. We do work with landowners to get their trees DNA tested and identified if they're interested. But despite maintaining the encyclopedia I linked in the other comment, we're a small group of volunteers (~6 people) and are mainly focused on a specific geographic region.