Upon researching, South Fork Reservoir boat ramp is located in Elko County, Nevada, with the coordinates mentioned in the question. It is a concrete boat ramp that is 20 feet wide.

The South Fork Reservoir boat ramp provides access to the South Fork Reservoir, which is a man-made reservoir with a surface area of 1,650 acres. The reservoir is primarily used for fishing, and the Nevada Department of Wildlife regularly stocks it with fish, including rainbow trout, brown trout, and catfish.

As for the types of craft permitted on the water, the Nevada Department of Wildlife states that motorized boats are allowed on the reservoir, but there is a strict speed limit of 5 mph. Additionally, water skiing and jet skis are not allowed.

In summary, the South Fork Reservoir boat ramp is a 20-foot wide concrete ramp that provides access to the South Fork Reservoir in Elko County, Nevada. The reservoir is primarily used for fishing and motorized boats are permitted on the water, but there is a speed limit of 5 mph and water skiing and jet skis are not allowed.