The Pine is the fast one. It drops harder than anything else in the northern Lower Peninsula — call it roughly seven feet per mile through the steeper stretches — and that gradient, fed by cold groundwater, gives you a clear, pushy, gravel-bottomed freestone that stays under about 69F even in August when the rest of southern Michigan's trout water is cooking. Everything in it is wild. Two strains of brown trout, brook trout in the colder upper water, and a McCloud-strain rainbow population that's genuinely unusual for the region — the Pine holds more wild rainbows than just about any other river in the Lower Peninsula, and they fight and jump like the West Coast fish they descend from. Because the whole fishable length sits above Tippy Dam there are no Lake Michigan steelhead or salmon runs here; the trout are stream-bred residents, and some of the browns get large because they aren't sharing the river with migratory fish.
It fishes differently than the famous Michigan flats water like the Au Sable or the Manistee. The current is quick and the bottom is loose gravel and sand with a lot of woody debris and sweepers, so wading is a careful, feet-shuffling affair and a wading staff earns its keep. Many anglers cover water in a raft or small drift craft because the river moves you along whether you like it or not, but this is a get-out-and-wade-the-runs river, not a big float fishery. Prospecting works well: dead-drift a big stonefly nymph — the Pine has good numbers of large Pteronarcys, sizes 2 to 6, and that year-round nymph game is how most people fish it — or swing a sculpin through the deeper bends and cut banks. Dry-fly windows exist, from Hendricksons and grannoms in spring through sulphurs, light cahills, and the June drakes, but the Pine rewards searching more than it rewards matching a single hatch.
The one thing you plan around is paddling traffic. From Memorial Day weekend through Labor Day the Elm Flats-to-Low Bridge corridor is one of the busiest canoe, kayak, and tube runs in Michigan — the Forest Service requires a watercraft permit on that stretch for exactly that reason — and on a warm summer weekend the flotilla makes daytime fishing there pointless. So you fish early mornings, evenings, and weekdays in season, or you wait for the floaters to thin after Labor Day. Fall is the quiet reward: crowds gone, big browns getting aggressive pre-spawn, and the whole river to yourself. Note that the Pine runs a short season — unlike Michigan's year-round trout streams it follows the traditional last-Saturday-in-April to September 30 trout season, closed October 1 through late April, so there's no winter fishing to fall back on.