The Oro-Medonte and Midland Trails are connected side trails of the ~500km Ganaraska Trail. The Oro-Medonte Trail runs north from the Ganaraska Trail and then continues on to Midland as the Midland Trail. Together they are 29.6km according to the ONDAGO app. The trail ends just off of the Tay Shore Trail, before the bridge, right across from Saint Marie Among the Hurons. This side trail has a lot to offer. Paved trail, snowmobile trail, some bushwhacking, hilly road section and nice single track. It is marked with white blazes. A map of the overall trail system is here: https://ganaraska-hiking-trail.org/?page_id=23
Note: This is different from the nearby Oro-Medonte Rail Trail, which parallels the coast of Lake Simcoe.