The P'tit Train du Nord is a 232-kilometre linear park that follows the old railway corridor north from Saint-Jérôme into the Laurentian highlands, passing through Sainte-Thérèse on the way. The Sainte-Thérèse access point is just north of the centre, with parking, a refreshment kiosk in season, and a small visitor map.
In summer it is a cycling route — flat, well-graded, and signed in kilometres so you can plan a half-day ride or a multi-day tour with overnight stops in the villages along the way. In winter it converts to a cross-country skiing trail. Bike rental is available a few stations further north in Saint-Jérôme if you arrive on the commuter train.