According to the latest information available, the boat ramp named State Game Road 11999 in Pierce County, Washington is a concrete boat ramp that is 12 feet wide. It provides access to the Alder Lake Reservoir, which is a 7-mile-long body of water created by the Alder Dam on the Nisqually River. The reservoir is used for fishing, boating, and swimming, and allows motorized and non-motorized watercraft, such as powerboats, sailboats, kayaks, and canoes.

It is important to note that regulations and permitted craft may change, so it is always advisable to check with the local authorities or park rangers for the latest information and rules before using any boat ramp or waterway.