According to the latest information available, the boat ramp named South Lake Ketchum Road Lake Ketchum in Washington is a single-lane concrete boat ramp that is suitable for small to medium-sized boats. The ramp is approximately 16 feet wide with a gentle slope. The body of water it services is Lake Ketchum, which is a small freshwater lake located in Snohomish County, Washington.

As per the Washington Department of Fish and Wildlife, the lake permits the use of electric motors, as well as non-motorized crafts like canoes, kayaks, and paddleboards. However, gas-powered boats are not allowed on the lake.

In conclusion, the South Lake Ketchum Road boat ramp is a single-lane concrete ramp that is approximately 16 feet wide. It services Lake Ketchum, a small freshwater lake in Snohomish County, Washington. Small to medium-sized boats are allowed on the lake, but gas-powered boats are not permitted.