One of the most scenic, and perhaps the most historic, trail in the Park is not a long trail, nor a hard one. It's an easy, short run for those looking for a beautiful little trail run before or after work. The Waterfall trail on the Mackenzie King Estate runs through a little piece of woods and by a waterfall, now dry. The Waterfall trail was William Lyon Mackenzie King's favourite trail. He used to spend hours wandering the trail, and when entertaining guests he would invariably bring them on the Waterfall trail. Many thanks to the NCC for preserving and recognizing the importance of the Estate and the trails surrounding it. The following is a detailed trail description of access points and trail choices.
The Larriault/Waterfall trail is a well maintained easy walking trail, less than 5 km long, with only small rolling hills. The trail is for pedestrians use only. It is closed to cyclists and it is not maintained for skiing. It is accessible from the Champlain Parkway and is near 4 parking lots: P6, the Mackenzie King Estate lot, the Larriault lot and the Mulvihill lake parking lot.
The trail can be started at the Mackenzie King Estate. If leaving from P6, walk south through the estate's ruins. There will be a paved and a dirt path that lead through the ruins; both will end up at the parking lot on the parkway. Once in the parking lot look for a wooden gate at the west end (to the right of one who is facing the parkway). Walk through this gate and go down a short hill. At the bottom of the hill there is a pedestrian tunnel that leads underneath the parkway. Go through this tunnel and continue straight ahead onto the trail afterwards. The trail will lead gradually downhill as it winds alongside a streambed. About 0.5km after crossing the parkway the trail will fork. The left fork leads down a short steep downhill and ends at a small terrace overlooking a dry waterfall. Take the right fork to continue along the Larriault trail. The trail continues on along with gently rolling hills until the Larriault parking lot. A short distance before the Larriault parking lot there is a viewpoint that overlooks the farm fields of Aylmer and the Ottawa River.
The Larriault and Lac Mulvihill parking lots are directly across the parkway from each other. There are picnic sites available at both. To finish the loop, follow the trail out the southeast side of the Lac Mulvihill parking lot. When heading back towards the Mackenzie King estate there are two major forks in the trail. At the first fork, stay to the right. The left fork leads to a gravel road and ends there. At the second fork, one can go either direction. The right fork leads directly back to the Mackenzie King Estate parking lot on the parkway. The left fork goes through Moorside and some of the estate gardens on its way back to P6. Both routes are quite short. I recommend the Moorside route as I find it adds more variety to the trip.
Runners traveling this loop who want to go for a longer distance can consider hooking into trail #35 at the Mackenzie King Estate. Trail #35 enters the Mackenzie King Estate grounds close to the parking lot on the parkway. Once on trail #35 one has a variety of options as trails #7 and #15 both connect to it.