Highway 41 begins in the centre of Lennox and Addington County at Highway 7, in the town of Kaladar. The highway once continued south to Napanee, but this is now County Road 41. The highway travels north through the Canadian Shield roughly following the Addington Colonization Road, straddling the boundary between Lennox and Addington County and Frontenac County. It serves the communities of Northbrook and Cloyne before entering Bon Echo Provincial Park. Within the park is the large Mazinaw Rock escarpment, which is visible from the highway.