Pickup country isn't just Texas and the Dakotas. It's the whole US of A, as shown in this map.
The map, created by Cox Automotive with January-September 2017 registration data from IHS Markit, shows the leading vehicle body style purchased in each U.S. county. Cars dominate in scattered urban markets and crossovers are making inroads. But the evidence is clear: In county after county, the U.S. overwhelmingly favors pickups.