>While the U.S. Border Patrol primarily operates within 100 miles of the border, it is legally allowed “to operate anywhere in the United States,” the agency added.
The Border Patrol probably is allowed to operate anywhere within the United States, but being in the Border Patrol doesn't (at least statutorily) give them any magic powers; in particular, you don't get "border search authority" by being a part of CBP, but rather by being any law enforcement officer confronting someone who you reasonably believe crossed the border recently.