There seems to be some confusion in the question as the coordinates provided are actually in Washington state, not Idaho. Therefore, I will provide information on the boat ramp in Spokane County, Washington.

The Spokane River Centennial Trail boat ramp is a concrete ramp located on the Spokane River, just downstream from the Monroe Street Dam. It is a popular launch point for kayaks, canoes, and small motorized boats, and is also used for fishing.

According to the Spokane County website, the boat ramp has two lanes and is 12 feet wide, which allows for easy access to the water. The ramp is also equipped with a courtesy dock, which provides additional space for boaters to load and unload their vessels.

The Spokane River Centennial Trail boat ramp services the Spokane River, which flows through Spokane County, Washington. The river is approximately 111 miles long and is a popular destination for recreational boating, fishing, and other water activities.

The kind of craft permitted on the Spokane River varies depending on the section of the river and the time of year. In general, motorized boats are allowed on the lower section of the river, but are prohibited on the upper section. Kayaks, canoes, and other non-motorized boats are allowed on most sections of the river year-round.

In conclusion, the Spokane River Centennial Trail boat ramp is a popular launch point for recreational boaters in Spokane County, Washington. It is a concrete ramp with two lanes and a courtesy dock, and services the Spokane River. Motorized boats are permitted on certain sections of the river, while non-motorized boats are allowed on most sections year-round.