POTSDAM -- The 6th annual Potsdam Sandstone Festival will take place Sept. 18 to 21 featuring demonstrations, lectures and new this year is a Raquette River Paddle Tour around Oak Island.

Participants on the tour can view the remains of the old Hannawa Falls Light and Power Company Railroad that island hopped across Oak and Sugar Islands.

A tour starting at the new boat launch in Ives Park on Saturday will teach attendees about the old railroad used to transport Potsdam Sandstone from the quarries just below Hannawa Falls to the Clarkson family stone cutting yards on Pine Street.

• Thursday, Sept. 18: noon guided tour of St. Mary’s Catholic Church, 17 Lawrence Avenue., and at 5 p.m. a guided tour of Zion Episcopal Church, 9 Main St., Colton.

• Friday, Sept. 19: 11 a.m. tour of Trinity Episcopal Church and Tiffany windows, meet at 8 Maple St., Fall Island; at 1 p.m. there will be a guided tour of the First Presbyterian Church, corner of Elm Street and Lawrence Avenue; at 4 p.m. there will be walking tour of Clarkson University’s First Building at Old Main, 51-53 Main St. in Potsdam. See the new renovations. Happy hour at Maxfields, 5 Market St., featuring live music and 50/50 raffle; at 5:30 p.m. there will be a walking tour of historic downtown, meet at Maxfields; at 7 p.m. the Plein Air Festival painting live auction, hosted by SLC Arts Council, will take place at Maxfields

• Saturday, Sept. 20: from 10 a.m. to 2 p.m. there will be coffee and crumpets sponsored by Emily V. Clarkson Moore at the Old Snell Hall Lawn, 1 Park St., across from the Civic Center. A walking tour of the Red Sandstone Trail in Hannawa Falls is set for 10 a.m. Meet at the trailhead across from the fire station on Mill Street near the bridge. The suggested donation is $5. The Snell Lawn Tent is set for 10 a.m. to 4 p.m. and will have paintings displayed and for sale from the Plein Air Festival. Also in attendance will be the North Country Children’s Museum, Graymont Stone with sample of sandstone from the quarry in Parishville and Jane Lammers of Red Squirrel Photography will have sandstone cards and art.

Also on Saturday there will be a guided tour of the Parmeter Hale House, 166 County Route 59, at the end of the Red Sandstone tour. Demonstrations teaching how to repair mortar joints in historic masonry buildings will be held with Roy Perry at 1 and 3 p.m. under the tent, Snell Lawn, 1 Park St. At 4 p.m.there will be a guided tour of Clarkson Land Office (Alchemistress) located at 17 Maple St. The paddler’s tour of the Hannawa railroad that crossed Oak Island is scheduled for 5 p.m. at the boat launch at Ives Park in Potsdam. Bring your own boat.

• Sunday, Sept. 21: A tour and talk about Bayside Cemetery with Susan and John Omohundro and Art Johnson will take place at 2 p.m. at the Gate House, Clarkson Avenue. The suggested donation is $5.

To make a donation to help with the festival, send a check to Potsdam Public Museum, P. O. Box 5168, Potsdam, NY, 13676. Donations are tax-deductible. Info: www.PotsdamPublicMuseum.org or 265-6910.