Warpath by the Mutant Wall.

The "Mutant Wall" was a 2000 mile long wall built along the US-Mexico border. Although publicly it was claimed to have been created to stop illegal immigration, in reality the truth was much more devious. It was a last ditch effort made by the US Government to try and stop the growing mutant rebels of the Zapatista Resistance. The wall was succesful in hindering mutant movement across the border.