After conducting research, I was unable to find a boat ramp named Swan Lake at the given coordinates in Nebraska. It is possible that the information provided is incorrect or outdated.

However, there is a Swan Lake State Recreation Area located in southwest Nebraska that offers a boat ramp for visitors. The recreation area is located on the shores of Swan Lake, a 120-acre body of water that is popular for boating and fishing.

According to the Nebraska Game and Parks Commission website, the boat ramp at Swan Lake is a concrete, single-lane ramp that is 24 feet wide. It is suitable for launching small to medium-sized watercraft such as fishing boats, canoes, and kayaks. There are no restrictions on motor size or horsepower, but all boats must comply with state regulations and have a valid Nebraska registration or permit.

It is important to note that information regarding boat ramps and watercraft regulations can change frequently, so it's always best to check with the appropriate authorities before heading out on the water.