BOULDER JUNCTION, Wis. (AP) — The iPhone app for the state's largest state forest has added another service.

The free application for iPhone, iPad and iPod used to only provide trail locations, maps and other information about the Northern Highland-American Legion State Forest in far northeastern Wisconsin.

But it's now adding the ability to check campsite availability. Reservations can be made through the online reservation system or by phone.

The 225,000-acre forest attracts about 3 million visitors a year. It was established in 1925 and features 930 lakes and 250 miles of rivers and creeks.

The forest's recreational specialist, Kimberly Krawczyk (KRAW-chek), says if visitors like the application the DNR would consider similar apps for other state parks.