AMP: 0 Location: East River Rd and US-89, Park Cty Reassurance shield as S-540 begins. AMP: 11 Location: East River Rd and Murphy Ln, Park Cty Several miles later, we’ll approach S-571. Turn left for unmarked 571 to Emigrant and US-89.  N to S-572  W to US-89  S to Yellowstone National Park (TO US-14/US-16/US-20/US-89/US-191/US-212/US-287), N to S-571