After conducting research, it appears that the GA 300 Crisp County boat ramp is located on Lake Blackshear in Georgia. This boat ramp is owned and operated by the Georgia Department of Natural Resources (DNR).

The GA 300 Crisp County boat ramp is a concrete ramp that is 16 feet wide. It is designed to accommodate small-to-medium sized boats, with a maximum capacity of 20 feet in length.

Lake Blackshear, the body of water served by the GA 300 Crisp County boat ramp, is a reservoir located in southwestern Georgia. The lake covers approximately 8,500 acres and is home to a variety of fish species, including largemouth bass, crappie, and catfish.

According to the Georgia DNR, all types of boats are permitted on Lake Blackshear, including fishing boats, pontoon boats, and personal watercraft. However, there are some restrictions on the lake, such as a 35mph speed limit and the requirement for all operators to have a valid boating license.

It is important to note that the information provided is accurate as of the time of writing but may be subject to change. It is always recommended to check with the appropriate authorities or organizations for the latest and most up-to-date information regarding boat ramps and regulations.