El Paso County sheriff's officials said the rancher alleged the two men were trespassing.
Norangel Velez told KTSM-TV in El Paso that he and his father were looking for land to buy when they took a wrong turn in their truck and the rancher began shooting without warning.
Velez was shot once and his father three times.
It's unclear if the rancher will face charges. The Texas Rangers are investigating.