Another Unusual Situation

The two highways in the far northwest corner of New Mexico cannot be reached from any other point in New Mexico. People have to go through parts of Colorado or Arizona to get there. No roads connect with these two highways. The nearest road in New Mexico is four miles away and it is a primitive dirt track on the Navajo Reservation. The nearest road, also unpaved, that can be driven by a passenger vehicle is six miles to the southeast. Between these two dirt roads and U.S. Highway 160 are the San Juan River, several miles of desert, Tohache Wash and then another strip of desert.
  This creates an unusual situation for the New Mexico Department of Transportation when it comes to maintaining the two highways in this corner of the state. The only way to get there is to go through either Arizona or Colorado. The nearest New Mexico Highway Department maintenance yard is in Farmington. To get to, say, the junction of U.S. Highway 160 and State Highway 597, the  highway maintenance crews have to drive 55 miles west and then turn northeast, in Arizona, and then drive 6 miles to the intersection, re-entering New Mexico 4/10 of a mile from the intersection. Nine miles of this route is in the northeast corner of Arizona. Another route they can take is to go twenty-nine miles west from Farmington and then turn north in Shiprock and head into Colorado on U.S. Highway 491. Six miles into Colorado, they would turn left, or southwest, onto Highway 160. Then they would have seventeen miles to travel to re-enter New Mexico and another half mile to arrive at the intersection. Twenty-three miles of this route are in Colorado.
  This interesting situation raises another question. What if there is a serious car accident on the short stretch of U.S. Highway 160 that is in New Mexico? I am assuming the New Mexico State Highway Patrol would respond, but they would have to drive through other states, where they have no jurisdiction, to get there. The Navajo Tribe has a police force, but they have very limited jurisdiction over non Navajos. Can a person speed like mad for 9/10 of a mile when they are driving on Highway 160 through New Mexico? What if there is some type of incident right on the Four Corners Monument itself? A person can easily step into another state and out of the jurisdiction of the arresting officer, even though the person is only a few feet away from the officer. I wonder if they have ever had any incidents like this?