Croton, N.Y. - Archaeologist Glen Keeton will discuss his discovery and excavation of the Tunkamoose Mastodon during a presentation on Sunday, June 10, 2 p.m., at the Croton Point Nature Center at Croton Point Park in Croton. Keeton, of the Orange County Chapter of the New York State Archaeological Association, discovered the tusks while canoeing with a friend on the Wallkill River in 2008. Visitors will be able to view these artifacts, one of which measures 9 ½ feet long and is dated at 14,500 years old. Keeton's presentation will also include a slide show of the find and its recovery. Admission is free; parking at Croton Point is $5 with a Westchester County Park pass and $10 without the pass. The event is presented by the L.A. Brennan Lower Hudson Chapter of the New York State Archaeological Association. Croton Point Nature Center, a Westchester County Park, is located at Croton Point Park on Croton Point Avenue in Croton-on-Hudson. Go to westchestergov.com or call the nature center at (914) 862-5297 for information.