This summer, we visited this National park run by Canada Parks. We didn't have a reservation, and we stayed in Shawinigan at a hotel, but we did have a chance to visit. We came in via the southeast entrance from Saint-Gerard-des-Laurentides and parked near Lac-à-la-Pêche at Saint-Gérard. We walked to the Parker waterfalls on the way to Parker lake.
There are three drive-in campgrounds: Mistagance, Wapizagonke, and Rivière-de-la-Pêche. The most hikes seem to be near Rivière-de-la-Pêche, but there are trails that interest me across the park. It may be a mistake to follow the beach icons, as the campground Wapizagonke doesn't list one even though it seems to be along the shore of a lake, but I am going to book us at Mistagance and RdlP if I can. If I found a willing partner, it would be quite a feat to canoe/portage up Lake Wapizagonke to hike up to Waber falls some day too.
Actually, there is a provincial trail in the Mauricie region that is 99 km long! It's part of a longer 1650 km network of trails called Le Sentier National, and it's free! It was a collaboration between 9 regions including the Mauricie organized by La Fédération Québécoise de la Marche. I am inspired, especially if visiting the US is a few years off still, with the longer hikes laid out in detail, like this weeklong intermediate hike (divided into sections or "troncons"), or a shorter 4 day version, complete with elevation maps and shelter photos. The only caution is to avoid it during hunting season, that tourists might be tempted as it coincides with autumn colours. . I might have to join a hiking club. A website called RandoQuebec might help! Years ago, the bus for the group called Randonnee Aventure came close to my apartment, and I went a few places because of it! Maybe one day again!
Within the park, there are 5 maps of trails. They all look tempting! To narrow it down, since the next visit will only be for 3 days, I found an article that lists a top five beautiful places within Mauricie Park. It may not be scientific, but it gives me a template. I always like to find the lookouts (eyeballs on a map), and hiking to get there makes it seem even more worthwhile. From the southwest around to the southeast, Sentiers les Cascades et Les Falaises (Falls and Cliffs starts at Shewenegan picnic spot), Belvédère de l'Ile-aux-pins (up a short path with stairs between km 52 and 53), Belvedere du passage (view of Wapizagonke lake), Sentier du Lac-Solitaire (Pavillon RdlP, 3 hour loop, et Belvédère du Lac-Bouchard (between km 8-9 near Saint-Jean-des-Piles)