The idea that Maya traders ported macaw feathers a couple thousand kilometers to Colorado would indeed be controversial. Contact and trade between the American Southwest/Northwest Mexico (aka Oasisamerica/Aridoamerica) and Mesoamerica is no so controversial. The flourishing of ancestral Pueblo groups (e.g. in Mesa Verde and Chaco Canyan) coincided with the Late Classic/early Postclassic/Epiclassic in Mesoamerica, the times of the Toltecs, El Tajin, Chichen Itza, and, perhaps more importantly, a series of polities stretching northward from Western Mexico such as La Quemada, Casas Grandes, and Alta Vista which served as a trade route to ferry goods like macaw feathers to the north.

The implications are not that this was direct trade, but that it was carried out by intermediaries, which nonetheless resulted in things like macaws (and their feathers) being transited northward, and even bred locally (Minnis et al. 1993). There are also less firmly established aspects of Mesoamerican culture diffusing northward to influence the Kachina cult (James 2000), but the presence of things like Mesoamerican style ballcourts popping up in SW USA/NW Mexico is well documented (Whittington 2001, Whalen & Minnis 1996, McGuire 1980). Oh, and chocolate too (Crown & Hurst 2009)

The classic theory is that Mesoamerican goods and ideas (macaws, ballcourts, chocolate, etc.) flowed north in exchange for turquoise flowing back south. This is pretty much the whole thrust of Phil Weigand's career and anyone talking about turquoise is really building on his work. That said, Nelson 1995 and pretty much the whole CV of Sharon Hull have been doing some interesting work in expanding, exploring, and complicating the turquoise trade. I'm going to ping /u/RioAbajo here, because I think this is more his area.

So the macaw feathers your friend got told about probably do exist! It's just that they weren't ported directly by a bunch of Maya up to Colorado, but more likely came via intermediary trade or possibly even local breeding of birds. The "collapse" of this trade network comes with climate changes which saw increasing aridity of both the Southwest and Northern Mexico (aka, the Medieval Warm Period if you're some sort of smug Medievalist). Local environmental concerns (such as overpopulation and deforestation) have been linked to both the decline of ancestral Puebloan peoples, but also as the impetus for groups in the Gran Chichimeca of the central Mexican Plateau to move southwards, which would eventually lead a semi-nomadic people known as the Mexica to settle down and start the chain of events which spawned the Aztecs.

Two types of macaw are found archaeologically in the U.S. Southwest/Mexican Northwest. The skeletal remains of both military macaws (Ara militaris) and scarlet macaws (Ara macao) are found archaeologically over a very broad region. Hargrave (1970) compiled all the known archaeological examples, which cover an area roughly from Phoenix, AZ in the West (at the Gatlin Site) to Pecos Pueblo and Gran Quivira Pueblo in east-central New Mexico. Macaws are fairly abundant along the Mogollon Rim between southern Arizona and New Mexico, and at the large site of Paquime in Chihuahua, Mexico. The northernmost macaws are from the Kayenta region in northern Arizona on the Navajo Reservation, at Kiet Siel Pueblo. In New Mexico, Chaco Canyon in northwestern New Mexico marks the northernmost extent. Hargrave doesn't list any macaws documented archaeologically in Colorado at all, let alone at Mesa Verde.

Other lines of evidence point at the prominence of macaws as significant ritual items, including depictions in pottery both as effigies and in painting. Significantly, breeding pens with macaw eggshell were identified at the site of Paquime in northern Chihuahua. Paquime and the surrounding area is currently the only known regionin the Southwest with evidence for breeding macaws, rather than simply importing them (Minnis et al. 1993: 270). This effigy vessel from the Chihuahua area (number 1 on the shelf) depicts such breeding pens.

The value of macaws to Southwestern cultures is twofold, being both a rare species (thereby adding to the prestige and value of the birds) as well as being a source of brightly colored feathers, which are significant in most Southwestern cultures because of their associations with rain and rainmaking. The ritual significance of rainmaking is of the highest importance for agriculturalists living in an arid environment with significant environmental variability in terms of annual rainfall, and so the tremendous effort in acquiring exotic macaws makes sense within that framework.

As for how they were procurred, other than breeding in northern Mexico in the 13th and 14th centuries A.D., there isn't any direct evidence of trade in macaws between the U.S. Southwest/Mexican Northwest and the Maya area of southern Mexico, Belize, Guatemala, and Honduras specifically. Instead, the evidence only points to trade with people living in the wide geographic region with access to these macaw species, much of which is closer to the Southwest than the Maya area. Here it is important to point out the differing geographic ranges of the two macaw species seen archaeologically. The military macaw is much more easily acquired in the Southwest, being native to Sonora and other parts of northern Mexico. The scarlet macaw, on the other hand, is very much a tropical bird and is only endemic to parts of central and southern Mexico. The nearest habitat to the Southwest in which scarlet macaws could have been acquired is in Veracruz, Mexico.

The scarlet macaw was probably more valued than the more local military macaws as scarlet macaws occur much more frequently archaeologically. Indeed, even in Chihuahua where military macaws are semi-local, the archaeological examples are skewed heavily towards scarlet macaws instead (Minnis et al. 1993: 270). Out of the 145 specimens examined by Hargrave, only one was identifiable as a military macaw, 101 were identifable as scarlet macaws, and 44 were not identifiable at the species level (Hargrave 1970: 53).

Interestingly, Hargrave found that the overwhelming majority of macaws were juveniles, with 71% between 11-12 months old, 13% between 4-11 months old, and 13% between 1-3 years old (Hargrave 1970: 53). Young macaws may have been preferred for a certain resilience in transport, especially through arid environments foreign to the species. The age at which the macaws were killed is also an age at which their plumage would be coming in, supporting the supposting that they were primarily used as a source of plumage.

These long-distance trade routes with Mesoamerica are well attested in a number of other ways. Exchange of ideology and materials between the U.S. Southwest/Mexican Northwest and Mesoamerica has considerable antiquity. For the macaws, the earliest are found in Chaco Canyon and recent work has dated these early birds to between A.D. 900-975 (Watson et al. 2015). The majority of other macaws date to after A.D. 1000 (Hargrave 1970: 54). Likewise, the presence of chocolate at Chaco Canyon in the same time period is a huge indicator of trade with Mesoamerica, cacao being a tropical plant, again growing in Veracruz at the closest (Crown and Hurst 2009). The residue analysis that detected traces of cacao (theobromine and caffeine) were conducted on cylinder vessels which resemble the cylinder vessels known to have been used in Mesoamerica for making chocolate drink. Rubber balls (rubber being a tropical product) found in the Hohokam area (southern Arizona) along with ball courts (a highly typical Mesoamerican architectural feature) also indicate the exchange of ideas and goods. Worked copper bells (likely from Western Mexico) are further evidence of exchange with Mesoamerica.

As for collapse of this network, the exchange of these rare goods seems to flourish primarily between A.D. 1000-1300/1400. Importantly, after about A.D. 1275 there is really significant reorganization of societes in the Southwest with huge migrations (for instance, out of the Mesa Verde region) and a lot of changes to religious practice and the stratification of society. The collapse of this trade network is "controversial" in the sense that there isn't any real archaeological consensus on why these Mesoamericas imports were no longer imported, but there is a fairly good correlation between a significant decrease in Mesoamerica imports (though importantly, not a total lack of imports) at about this same time period in the late 13th century when the entire Southwest underwent significant social changes and reorganization.

Edit: Typos.

Sources:

• Crown, Patricia L. and W. Jeffrey Hurst. 2009. Evidence of cacao use in the Prehispanic American Southwest. Proceedings of the National Academy of Sciences of the United States of America, , 106(7): 2110-2113.

• Hargrave, Lyndon L. 1970. Mexican Macaws: Comparative Osteology and Survey of Remains from the Southwest. Anthropological Papers of the University of Arizona, No. 20. University of Arizona Press, Tucson.

• Paul E. Minnis, Michael E. Whalen, Jane H. Kelley and Joe D. Stewart. 1993. Prehistoric Macaw Breeding in the North American Southwest. American Antiquity, 58(2): 270-276.

• Watson, Adam S., Stephen Plog, Brendan J. Culleton, Patricia A. Gilman, Steven A. Leblanc, Petere M. Whiteley, Santiago Claramunt, and Douglas J. Kennet. 2015. Early procurement of scarlet macaws and the emergence of social complexity in Chaco Canyon, NM. Proceedings of the National Academy of Sciences of the United States of America, 112(27): 8238-8243.