The law in a STATE 1 county requires liquor stores to close at 9:00 pm. Fortunately for those residents of this county who want to do some late night drinking, they can park in a parking lot in STATE 1 and easily walk from their cars directly into a liquor store in STATE 2 to buy spirits until midnight. They're able to cross the border this easily because the river that served as the original border between this area of STATE 1 and STATE 2 shifted its course over the years. Upstream of the border between STATE 1 and STATE 2, this river is not a border between states. Downstream, this river is a border all the way until its mouth.
Texas and New Mexico