Inscription of a site in UNESCO's World Heritage list involves a long and relatively complex process. Member states first select sites to be included on a "tentative list". In the United States, even this process includes an open process. Then sites from the tentative list are selected, and full proposals are prepared. The proposal includes both an explanation as to why the site is of sufficient importance to be considered as part of the world heritage of mankind and a plan for the maintenance and conservation of the site. Proposals in hand, member states then make nominations for the full World Heritage list. These are peer reviewed, and on the basis of those reviews the governing body of the World Heritage Center makes the decision to accept or reject the site.
The U.S. government last month began the process of selection of sites from the tentative list for preparation of full proposals. Here is the current tentative list for the United States:
I have visited many of these sites. I have chosen two for illustration of this post, in part because they seem to be little known among my fellow Americans and in part because they show that the North American pre-Columbian population had achieved much higher levels of intellectual attainment than is generally recognized. The Serpent Mound, for example, is not only a huge earthen structure (note the size of the people relative to the height of the mound), but are built demonstrating a detailed and complex understanding of astronomy and the prediction of the seasons.