We're planning a trip through New Mexico, Arizona, and Utah. My son is studying WWI, and I'm wondering if there are any museums, still-extant factories or the like that we can tour on the trip. If anyone could point me to an online resource for locating WWI-tourism destinations in the US, that would also be helpful.
For small memorial plaques and the like, you can consult the American Memorials Directory and the Historical Marker Database, which turn up a handful of memorials. The only one that makes the list of the "Doughboy Center's" list of AEF memorials is the World War I memorial outside the Mohave County Court House in Kingman, Arizona. It has one of only seven publicly accessible copies of the "Spirit of the American Navy" statue by E.M. “Dick” Viquesney, and is the only place in the world where it is displayed on the same pedestal as Viquesney's more famous "Spirit of the American Doughboy."
Of course, you can expect some treatment of World War I at the general history and military museums in the region, like the Arizona Military Museum in Phoenix.
But there are relatively few sites devoted to the First World War in the U.S. compared to Europe. The U.S. participation in WWI was relatively brief, and the war occupies a much smaller cultural footprint, overshadowed not only by World War II but by the U.S. Civil War. This goes double for the desert Southwest which then was even more sparsely populated than today. There were no major population centers, and there was no major manufacturing or research that took place there. The conflict that stands out from that era is the raids of Pancho Villa in 1916–17. Military tourism, meanwhile, is centered on yet another era, featuring sites like the National Atomic Testing Museum and the Trinity atomic bomb testing site.
You will probably be hard pressed to find World War I memorials or other related sites in the West.
As far as factories are concerned I would think that most of those would be on the East Coast but you can try looking for anything that still exists but I wasn't able to find any.