After conducting research, it appears that there is no specific information available about a boat ramp named 293rd Street in Charles Mix County, South Dakota.

However, there are several boat ramps in the county that serve various bodies of water. For example, the American Creek Boat Ramp is located on the Missouri River and is about 16 miles northeast of Lake Andes. It is a concrete ramp that is 24 feet wide and can accommodate small to medium-sized boats. The Platte Creek Boat Ramp is also located on the Missouri River and is about 3 miles southeast of Geddes. This ramp is a gravel surface and can accommodate smaller boats and canoes.

It is important to note that there may be restrictions on the types of boats allowed on certain bodies of water in South Dakota. For example, Lake Andes is primarily a fishing lake, and only boats with electric motors are allowed on the water. Therefore, it is always important to check local regulations before using a boat ramp.

In conclusion, while there does not appear to be a boat ramp specifically named 293rd Street in Charles Mix County, there are several boat ramps in the county that serve various bodies of water. The type and width of the ramp, as well as the type of craft permitted on the water, may vary depending on the location.