|Original cover from|
Journal of Book of Mormon Studies
As near as I can tell, the primary source that the Mesoamerican proponents rely on to reject the New York Cumorah from an archaeological standpoint is an article by John E. Clark titled "Archaeology and Cumorah Questions," published by the Journal of Book of Mormon Studies, 13/1-2 (2004): 144-51, 174.
Brant Gardner cites it on p. 377 of his 2015 Traditions of the Fathers, introducing the second part of the quotation below with this: "Countering the force of traditional association is the archaeological data for the hill and the surrounding area. John E. Clark discusses the reasons that the New York hill could not have been the location of the final Nephite battle." (emphasis added)
In this article, Brother Clark reaches a definitive conclusion: "I am unaware of any archaeological investigation of the hill itself, but sufficient information is available for the surrounding regions to make a critical assessment. Mormon’s hill and Moroni’s hill are not one and the same... Archaeologically speaking, it is a clean hill. No artifacts, no walls, no trenches, no arrowheads. The area immediately surrounding the hill is similarly clean. Pre-Columbian people did not settle or build here. This is not the place of Mormon’s last stand. We must look elsewhere for that hill."
Brother Gardner's deference to Clark's article appears typical among Mesoamerican advocates. "Archaeology and Cumorah Questions" is cited on the FairMormon page here. It is found on the BMAF page here. It's not on BookofMormonCentral.org, but probably will be once BOMC merges with BMAF.
When you read the article along with me, I think you'll be as astonished as I was that scholars would even cite the article, let alone defer to it. But then again, we're dealing with Mesoamerican seers who are content with bias confirmation and can't unsee their theories. If I haven't offered enough examples of that yet, you'll enjoy this one. It's a lot of fun.