just into Chihuahua and Nuevo León. It occurs at low to moderate altitudes, from 450–700 m on the Edwards Plateau and from 1200–1800 m in the rest of its range. It is scarce, with small, scattered populations usually on dry, rocky sites and arroyos where bare rock lowers the likelihood of wildfire spreading easily. Uses The edible seeds are occasionally collected like those of other pinyons, and sold as pine nuts. However, in its barren, dry habitat, infrequent and small crops are normal, reducing its economic value. It is occasionally planted as an ornamental tree, where its remarkable tolerance of drought and even semi-desert conditions makes it valuable in hot, dry areas. The papershell piñón and Cabeza de Vaca Pinus remota has importance in determining the route of Spanish explorer Cabeza de Vaca, the first European to explore Texas and the northern part of Mexico. Writing an account of his experiences, Cabeza de Vaca said that in 1535 the Indians of the region through which he was passing gave him and his companions pine nuts to eat which were "better than those of Castile [Spain], because they have very thin shells." In attempting to determine the route followed by Cabeza de Vaca from near the area of Galveston, Texas on the Gulf of Mexico to the Pacific Ocean coast of Mexico, several scholars, notably Cleve Hallenbeck in 1940, believed that the statement by Cabeza de Vaca referred to the seeds of Pinus edulis, the Colorado piñón, which is found in the mountains of southern New Mexico and adjacent Texas—but not in northeastern Mexico. The Mexican piñón (Pinus cembroides) found in Mexico has thick shells, rather than the thin shells described by Cabeza de Vaca. Therefore, Hallenbeck concluded on the basis of the range of piñón species that Cabeza de Vaca had traversed Texas westward from near Galveston to southernmost New Mexico and crossed the Rio Grande river near El Paso, Texas. To the contrary, Alex D. Krieger in a doctoral dissertation (1961) proposed instead that Cabeza De Vaca had traversed the coast of Texas, crossed the Rio Grande into Mexico and turned northwest, passing near present-day Monclova, Mexico and proceeding through Mexico to meet the Rio Grande again near present-day Presidio, Texas. Krieger's trans-Mexican route for Cabeza de Vaca was dismissed by proponents of a trans-Texas route because no piñón with thin shelled seeds was known to be native to