Stratigraphy of the Tucumcari area--A historical account
— Barry S. Kues

Tucumcari Mountain (elevation 4956 ft or 1511 m) rises about 750 ft (229 m) above the surrounding valley surface some 2 mi (3.2 km) south of the town of Tucumcari (Fig. 1). It was one of the first geographic features to become known to Americans south of the Canadian River in New Mexico and has long been a landmark for travellers entering New Mexico across the Llano Estacado. Together with other isolated remnants of the Llano in the area, it was involved in one of the most bitter controversies in the history of American geology, and even its exact location was disputed nearly 50 years after it first appeared on a map. The history of the Tucumcari Mountain area and the development of our understanding the stratigraphy of east-central New Mexico are intertwined, and both are summarized here. This paper complements a summary of early geological explorations in east-central New Mexico found elsewhere in this guidebook (Kues, 1985). Figure 2 shows the location of places mentioned in the text.

A major focus of this paper is the controversy over the age of the formations exposed in the Tucumcari area that resulted from Jules Marcou's geological studies while a member of the Whipple expedition in 1853. This controversy pitted Marcou against most of the leading American geologists of the mid-nineteenth century and attained a level of rancor and antagonism that few other geological disputes have matched. Normally such stratigraphic disagreements are settled easily and amicably between geologists as data and observations accumulate, but in this case the antagonism escalated far beyond consideration of the immediate questions in the Tucumcari area and was vented in literally dozens of publications in the 1850's and 1860's. In this atmosphere, rational assessment of the evidence often was submerged beneath personal invective, and the ill-feeling thus generated between the main disputants hung like a dark cloud over early studies of western Mesozoic stratigraphy far beyond the boundaries of New Mexico. All of this indicates that much more was involved than a mere difference of opinion on the stratigraphy of east-central New Mexico. In this paper, the  original dispute and its revival in the late 1880's and 1890's are described in considerable detail, in order to document and elucidate this fascinating intrusion of personality and emotion into nineteenth-century geological studies.