Sodom and Gomorrah, Texas, by R. A. Lafferty, Science Fiction, Fantasy

¿. . . .He knew better.
But he did write a nice round hand, like a boy's hand. He knew Spanish, and enough English. For the sector that was assigned to him he would not need a map. He knew it better than anyone else, certainly better than any mapmaker. Besides, he was poor and needed the money.
They instructed him and sent him out. Or they thought that they had instructed him. They couldn't be sure.
"Count everyone? All right. Fill in everyone? I need more papers."
"We will give you more if you need more. But there aren't so many in your sector."
"Lots of them. Lobos, tejones, zorros, even people."