Why is there a sudden drop-off in development here in Northern Mexico?

Is the Chicago metro area the largest population center near a time zone boundary in the world?

Climate in US (210.

Af – Tropical rainforest climate, Am – Tropical monsoon climate, Aw – Tropical savanna climate, BSh – Hot semi-arid climates, BSk – Cold semi-arid climates, BWh – Hot desert climates, BWk – Cold desert climates, Cfa – Humid subtropical climate, Cfb – Oceanic climate, Cfc – Subpolar oceanic climate, Csa – Hot-summer Mediterranean climate, Csb – Warm-summer Mediterranean climate, Cwa – Humid subtropical climate, Cwb – Subtropical highland maritime climate, Dfa – Hot humid continental climate, Dfb – Warm humid continental climate, Dfc – Subarctic climate, Dfd – Subarctic climate, Dsa – Hot humid continental climate, Dsb – Warm humid continental climate, Dsc – Subarctic climate, Dwa – Humid continental climate, Dwb – Warm humid continental climate, Dwc – Subarctic climate, ET – Tundra climate.