Who would have thought that there would have been people with elongated skulls in North America?
Already in 1936 it was thought that dolichocephalic people, with long skulls, had migrated to the Americas from other places in the world.
Text between square brackets  and bold emphasis are mine.
Hooton, Dixon and others agree that the first immigrants to the New World were dolichocephals. To Hooton it appears that the earlier dolichocephals of the American population probably had a blend of Mediterranean, Negroid and an archaic white element, subsequently glossed over with Mongoloid traits due to mixture with other immigrants. In any case we have evidence of dolichocephaly among the Basket Makers, whose remains stratigraphically are earlier than the Pueblos. There are also a number of cases where extreme dolichocephalic skulls have occurred under conditions indicating considerable age. The Lagoa Santa skulls from Brazil represent such a case. Extreme dolichocephals have been found in west central Texas, and along the Texas coast. The incomplete skull from Vero is according to Dr Hrdlička a skull with a cephalic index near the upper limits of dolichocephaly. The Punin skull from Ecuador is also dolichocephalic. The Minnesota skeleton reported in the last few years and an even more recent discovery -that announced by Figginsls- are both narrow-headed. So that while the actual dating of these and other similar skeletal material remains doubtful, they do seem to bear out the impression that early man in America was narrow-headed, and that many of the skulls, although they appear to be of the same general type as those of the surviving Indians, show characteristics that are Australoid. Regarding this question Sir Arthur Keith thinks the Punin skull shows unmistakable Australoid affinities.
Even in the late 1800’s it was clear that elongated skulls, or dolichocephalic people were once numerous in North America.
In Observations upon the Cranial Forms of the American Aborigines, based upon Specimens contained in the Collection of the Academy of Natural Sciences of Philadelphia, 1866, J. Aitken Meigs, M. D., comes to the conclusion that:
1st. That the crania of the Aboriginal Americans are divisible into Dolichocephalic [long skull], Mesocephalic [between long and round skulls] and Brachycephalic [round skull] groups.
2d. That the Dolichocephali greatly preponderate in numbers over the Mesocephali and Brachycephali.
3d. That in the case of the Peruvian skulls in the Academy’s collection, however, the short, square heads are more numerous than the elongated forms.
4th. That in North America neither the Dolichocephalic nor Brachycephalic tribes, when first known to Europeans, were restricted in their geographical distribution to any particular locality. While the former were scattered over the continent, through all degrees of latitude and longitude; the latter appear to have been, if we may judge from the specimens in the Museum, more numerous about the Great Lakes, at various places in the interior, in the south near the Gulf of Mexico, in the so-called Paduca area, and especially along the north-west coast. In general terms we may say that on the eastern or Atlantic side of the continent the Dolichocephali appear to have prevailed ; and on the western or Pacific side the Brachycephali. This in a great measure seems to have been, and still is the case in South America.
5th. That long and short-headed tribes or races are very commonly found throughout the two Americas side by side. In the extreme north, for example, dolichocephalic and brachycephalic forms are contrasted in the Esquimaux and their geographical neighbors, the Konaegior Kadiakan Aleutians; and again in the far south these diverse forms are exhibited in the Patagonians and Puelches.
6th. That this contrast in cranial forms existed among the extinct races of America, as it now does among extant tribes.
7th. That in comparing the old and new worlds by their cranial forms, we find that while in Europe and Asia the brachycephalic is the prevalent form, in North America the dolichocephalic is the predominant type.
8th. That while in Africa all the people are dolichocephalic, in South America they are nearly equally divided between the long and short forms.
9th. That while in Europe and Asia the Polar or Arctic people are chiefly brachycephalic, in America they are wholly dolichocephalic.
10th. That various European, Asiatic and African crania, such as those of Norwegians, Swedes, Anglo-Saxons, the Germanic or long-headed Germanic, the Gothic or short headed Germans, the Finns, Lapps, Turks, Sclavonians, Kalmucks, Burats, Prognathic Negroes, &c, find representatives among the native cranial forms of America.
11th. That this homoiocephalic representation is not confined to normal skull-forms, but is shown in abnormal or artificially distorted skulls also.
12th. That the Dolichocephali are divisible into at least six well-marked forms or types, viz. : the pyramidal, boat-shaped, oral, cylindrical oblong and arched.
13th. That the Brachycephali may be divided into round or globular, and square or cuboidal classes.
14th. That the Mesocephali also consist of two sub-groups, one of which is transitionary to the square or cubical, and the other to the round or globular Brachycephali.
15th. That these ethnical or typical groups are founded upon osteological differences as great, and apparently as constant, as those which, in Europe, suffice to separate the Germanic and Celtic stocks on the one band, from the Ugrian, Turkish and Sclavonian, on the other.
So, where are all those excavated elongated skulls? I guess in the basement of the museums, as usual, with everything else we are not allowed to know. Only a few pictures are available:
(the Sanders Mountain picture is from a bulletin board)