From there, the highway heads north, paralleling the shore of Banks Lake for much of the southern part of the route.

[2] The highway then heads northeast, crossing the Columbia River just north of the Grand Coulee Dam.

[3] On the north side of the Columbia, State Route 155 turns west and traverses the Colville Indian Reservation, passing through the communities of Nespelem and Disautel, crossing Disautel Pass at an elevation of 3,252 feet (991 m).

It continues west from the US 97/SR 20 underpass and crosses over the Okanogan River before ending at an intersection with SR 215.

[citation needed] WSDOT plans to rebuild the spur route's crossing of the Okanogan River in 2025 with wider lanes by replacing the sidewalks with a parallel pedestrian bridge.