From the tangled confluence with the Bitterroot River west of Missoula, to the Class-III and IV whitewater of Alberton Gorge, to the lengthy reservoirs behind dams at Thompson Falls, Noxon and Cabinet Gorge, the second half of the Clark Fork bears no resemblance to its upper reaches.
The fishing changes considerably too. Noxon Rapids Reservoir hosts more bass tournaments than any other waterbody in the state, according to FWP records.
Between the Bitterroot and Flathead confluences, the Clark Fork holds predominantly rainbow and cutthroat trout, with about 5 percent browns and less than 3 percent bulls. Catchable fish range from 200 to 600 per mile. This area fishes particularly well in late summer and fall, when upper reaches are hurting for water flows.
The waters above Kelly Island are restricted to float/wade fishing only. Motorized craft are allowed on some sections of the Clark Fork. The dozen miles of the Alberton Gorge contain some mighty trout, but require either a skilled whitewater boater or some steep hiking to reach the pools.
Anglers in spring recommend March browns, skwala, salmonfly, golden stone and grey drake patterns. In summer, caddis, trico, PMD, hoppers, and beetle/ant patterns predominate. In fall, hoppers, beetle/ant, caddis and PMD patterns tend to bring fish.
State fishing access sites abound along the Lower Clark Fork, especially between Missoula and St. Regis. They include two sites on Kelly Island, Kona Bridge, Deep Creek, Harper’s Bridge, Erskine, Petty Creek, Natural Pier, St. John’s, Cyr Bridge, Lower and Middle Osprey, Tarkio East, Tarkio, Ralph’s Takeout, Forest Grove, Big Eddy, Dry Creek and St. Regis.
The river makes a zig-zag back east to catch the Flathead confluence, and then west to head for the Idaho border after Paradise. Pair-A-Dice and McKay Landing are the only state access points between Paradise and Thompson Falls, where a series of dams change the river character.
Northern pike of 20 pounds or more can be found in these lower waters, along with growing numbers of large- and small-mouth bass, crappie, and yellow perch in the wide, slow waters. Trout remain around 500 per mile, but anglers report extremely erratic concentrations of fish followed by stretches of vacant water.
-- Rob Chaney, Missoulian