The Combination Building is a T-shaped building constructed with split field stone. It provides space for a picnic shelter, concession, and kitchen for campers. The overall dimensions of the building are 47'6" by 23'0". The shelter is located in the long section of the "T" while the kitchen and concession area are located in the shorter section. The 16'6" by 12' kitchen contains a sink and counter, and once provided space for two cast iron stoves. The 12' by 8' concession features a counter on the east facade and a window opening covered by an oak grill on the north. Both rooms open into the shelter area.

The shelter may be entered through either the east or west facades. Each has a 16'6" opening that is divided into three bays by oak posts topped by wooden lintels. The shelter contains a massive split stone fireplace with a segmental arch.

The building is entirely of split stone construction except for the gable areas, which are infilled with 1" x 10" rough horizontal boards. Only the shelter serves its original purpose.