Down River

  From the south end  of Yuma, it is an 18 mile drive to the end of U.S. Highway 95. The highway ends at the border with Mexico. The highways makes quite a few twists and turns through the flat, fertile farmland of the area. The soil was laid down over the eons by the once mighty Colorado River. Lettuce seems to be the most prevalent crop, although many other crops are grown in this area as well. While driving Highway 95, the Colorado River is never more than 2 or 3 miles away.
The first town south of Yuma is Somerton, which has about 14,000 people. Somerton is only 101 feet above sea level. Seven miles south of Somerton is Gadsden, which has about 1,200 people. It is an unincorporated community that was named for the Gadsden Purchase, which brought this area into the United States when  it was purchased from Mexico in 1853. The  president of Mexico at the time was still Jose Lopez de Santa Anna, who was president, actually dictator, during Texas's fight for independence in 1836. He sold the land that his northern neighbor coveted to earn money to pay off a huge war debt. This action proved so unpopular that it drove Santa Anna out of office in disgrace.
  Five miles south of Gadsden is San Luis, the second biggest town in Yuma County with about 31,000 people. San Luis is located in the far southwest corner of Arizona. It is bordered by Mexico on 2 sides, the south and west. The border on the west side is the usually dry Colorado River and the southern border is a high, steel fence that spans the sering desert. Although San Luis is an extremely poor community, it does not look as poor as many I have seen because, since it has been growing at such an explosive rate, most of the housing stock is new or somewhat new, less than twenty years. Also, nearly every street in town is paved and has curbs and gutters. Not something I would expect to see in a town where the yearly per capita income is only $5,377. This figure qualifies San Luis as one of the poorest towns in the United States. San Luis is typical of many towns on the Mexican border in that Spanish is the most commonly heard language on the streets.  The explosive growth of San Luis has spilled out onto the sand dunes east of town.
  Towns in Arizona put their elevation on their city limit signs. I have a problem with the posted elevation for San Luis. The city limit sign says that the elevation is 130 feet above sea level. That would make San Luis 29 feet higher than Somerton even though it is downstream from Somerton, closer to the river's vanished delta. The official lowest point in Arizona is 70 feet above sea level at the point where the Colorado River meets the border with Mexico. Notice I did not say 'flows into Mexico.' The river does not flow into Mexico anymore because it has been completely siphoned off for human use above this point. Anyway,  there is a small bluff a few feet high on the American side of the Colorado here, but it does not account for that 60 foot discrepancy. I would say the elevation of San Luis, at least in the downtown business district, is about 77 to 80 feet above sea level. Furthermore, that 70 foot figure was taken when the Colorado used to flow into Mexico. Was that figure taken at the normal water surface or at the river bottom? The official description says "At the point where the  Colorado River flows into Mexico." Since it does not flow into Mexico anymore, does that mean the lowest point in Arizona is less than 70 feet above sea level now?
  Just south of the big, ugly, imposing border wall lies the city of San Luis Rio Colorado, Mexico. It lies in the northwest corner of the state of Sonora, across the dry Colorado River from the state of Baja California. San Luis Rio Colorado has approximately 250,000 people and is one of the fastest growing cities in Mexico. I crossed the border here once, in 2000, and explored a good sized chunk of the central city on foot.