Development and looting are destroying archaeological sites everywhere in the world at a rapid and accelerating rate. In the lower Ulúa Valley, for example, almost all known sites have been seriously damaged or entirely destroyed by these activities. The only sites that have not been damaged are those deeply buried in alluvial deposits.

The intensity of site destruction by development activities -- especially large-scale mechanized agriculture and construction for industrial and housing development -- has given rise to an archaeological subfield variously called Cultural Resource Management (CRM), public archaeology, salvage archaeology, or contract archaeology. In the United States, federal and state legislation require that many construction projects undertake archaeological investigations in advance in order to assess their impact on archaeological sites. Where the impact is shown to be severe, "mitigation" may be required: fuller investigation of the sites that will be damaged or modification of projects to allow for preservation of archaeological remains. Developers are often required to fund this work, which is typically carried out on a contract basis by private CRM firms, departments of large architectural and engineering firms, and branches of universities.

Looting -- illegal digging of archaeological sites -- is an even more serious threat to the archaeological record. Looting is driven by the international antiquities market, which is supported by individual collectors and museums that want to possess ancient objects. Many museums have become sensitive to the ethical issues and concerned about legal liabilities and have scaled back purchases of looted antiquities, or withdrawn from the market entirely. Many continue to accept looted objects as gifts, especially from generous patrons; since this generates tax advantages for the donors who bought the objects, it still supports the antiquities market indirectly. The number of individual collectors anxious to buy looted objects not declined. Most patronize antiquities dealers but some collectors buy directly from looters and a few commissioning the looting of particular sites and/or participate personally in the looting.

Choice objects command high prices, which creates an economic niche for fakers as well as looters. Technical analyses can expose some fakes, but in most cases they aren't relevant. Many archaeologists and art historians believe that their experience with objects known to be ancient allows them to recognize fakes, but this connoisseur-ship is rarely, if ever, developed systematically on the basis of objects excavated by archaeologists (as opposed to those "known" to be ancient because other connoisseurs have accepted them). Modern fakers are just as skilled as ancient artists and their work is unlikely to be recognizable except when they make mistakes.

Objects that do not come from documented archaeological contexts have almost no contribution to make to our understanding of the past. Even when we can be sure they are looted ancient objects rather than fakes (almost never), it is their archaeological contexts -- not just the site where they were found but the detailed circumstances of their manufacture, use, and discard -- that provide useful information about the past, not the objects themselves. In a sense, it doesn't matter whether the unprovenienced objects displayed by museums are fakes or not; they are aesthetically pleasing and, since they have passed muster in terms of connoisseur-ship, they are plausible representations of ancient styles. Fakes are preferable to looted objects in this context since their acquisition has not involved the destruction of archaeological sites.

What is lost when sites are destroyed in these ways is not only the information that archaeologists might have been able to extract from them, but an important part of the cultural heritage of the nations where they are located and of the descendants of their ancient inhabitants. Most looted objects end up in collections in the United States, Europe, and Japan -- not their countries of origin. National laws and international conventions and treaties prohibit the illegal excavation, export, and sale of antiquities, but enforcement is difficult, especially in poor countries, and it is often not a high priority for law enforcement. Some countries have undertaken campaigns to recover objects given to foreign institutions -- often the employers of the archaeologists who excavated them -- long ago when sensibilities were different. In a few high-profile cases, museums and collectors have agreed (or have been forced) to return objects to their countries of origin, but repatriation is still rare.

In most parts of the world, all archaeological sites are considered part of the national heritage and they are owned by the nation. In the United States, archaeological sites located on private land are the property of the landowner. Apart from a few legal constraints, landowners can do as they please with sites on their property. The Archaeological Conservancy, a private foundation, has implemented a distinctively American solution to this American problem: buying archaeological sites in order to preserve them. The Conservancy has saved nearly 500 sites so far.