I traveled part of SD 44 yesterday, south of the Badlands National Park boundary. I turned north on SD 377, to get back to I-90 via SD 240.
TM has SD 377's south end at SD 44 (fine), and its north end at SD 240. However, GMSV shows, and I saw,
an End SD 377 sign at the southern park boundary. Some
much older 2013 GMSV imagery has SD 377 signage within the park, at the junction with SD 240. I didn't look back at that junction for whether there is still SD 377 signage there.