One of the best sections of the Kootenai River is the 42 miles from Libby Dam to the confluence of the Yaak River. This tailwater fishery is loaded with big rainbows and is accessible to both wading and drift boats. It's also home to the Montana state-record rainbow: a monster 33-pound, 1-ounce fish caught in 1997 (just 4 pounds short of breaking the all-tackle record-a 37-pound rainbow taken in Idaho in 1947). Since Libby Dam was completed in 1972, river flows have been regulated and the high water characteristic of spring runoff has been moderated. As a result, water conditions in April are generally quite good. One of my favorite sections starts four miles south of Libby downstream to Kootenai Falls. (The section of river from the dam to the Route 37 bridge is closed until mid-May.) Spin-fishermen cast quarter-ounce gold or fluorescent orange spinners and spoons. Flyfishermen use Green Drakes and Brown Caddis in April and May along with Hare's Ear Nymphs and Woolly Worms. There is a four-fish slot limit: three under 13 inches and one over 18 inches. Residents pay $17 for a season license; nonresidents pay $15 for two days, $50 for the season. Contact: Montana Fish, Wildlife and Parks (406-293-4161); Kootenai Angler (406-293-7578).