Based on the information available, the boat ramp named Sheridan Lake Road 16451 is located in Rapid City, South Dakota and has a latitude of 43.98089218 and a longitude of -103.47438812. This boat ramp provides access to Sheridan Lake, which is a 375-acre reservoir located in the Black Hills National Forest.

The most recent information available indicates that the boat ramp is a concrete ramp and is approximately 18 feet wide. It is suitable for launching smaller watercraft such as canoes, kayaks, and small motorboats. However, larger boats may have difficulty launching from this ramp due to its narrow width.

The water in Sheridan Lake is suitable for fishing, boating, and swimming. However, it is important to note that there are some restrictions on the types of watercraft that are permitted on the lake. For example, wake boats and personal watercraft are not allowed on the lake, and all boats must have a valid South Dakota registration.

Overall, the Sheridan Lake Road 16451 boat ramp in Rapid City, South Dakota provides access to a beautiful and popular recreational area for boating and water activities.