It serves as a connection to SD 1806, linking it with the town of Kennebec and Interstate 90 (I-90).

SD 273 begins at an interchange with I-90 (exit 235); the road continues south as 315 Avenue.

It heads north to enter the town of Kennebec, passing a couple of businesses as it almost immediately has an intersection with SD 248 (former US Highway 16).

The highway crosses over a creek before passing along the western edge of downtown.

SD 273 passes through some neighborhoods before leaving Kennebec and traveling north through flat farmland for the next several miles.