US Highway 2 is the line that matters
This is the Douglas County Brule, the one that runs north 44 miles from the bogs near Solon Springs to Lake Superior, not the Florence County river on the Michigan line that shares its name and its own USGS gauge. The DNR's Brule River State Forest pages split it at the US 2 bridge in the town of Brule. Above the highway is a slow, spring-fed river that Superior Fly Angler calls one of the only true spring creeks in the whole region, with resident brook trout, the only salmonid native to the river, plus wild browns and rainbows. Below the highway is a different animal. Wally Balcerzak, writing for Great Lakes Angler, puts the lower river at 15 or more miles from US 2 to the mouth, with one stretch dropping 200 feet in 12 miles, and it is that gradient and the sea lamprey barrier near the bottom that make it a steelhead river.
The fishery is wild. The DNR's fact sheet says stocking was mostly curtailed in the early 1980s and the present trout and salmon population sustains itself by natural reproduction, and that of roughly 33,000 angler visits a year, about 27,000 are for steelhead, lake-run browns and coho below Highway 2 in spring and fall.
Stones Bridge to County B: the artificials-only water
Start at Stones Bridge on County S. From there down to County B the DNR describes the river as slow and wide and excellent for fly fishing, with the larger hatches from May through the end of June, and it is the reach the DNR names as the best of the resident brown and brook trout fishing. The land along it from Stones Bridge to just below County B is mostly private, so this is canoe water; Superior Fly Angler in Superior runs guided canoe trips on it through the summer for brook, brown and rainbow trout and the Hex. Two state forest campgrounds sit on the river, Bois Brule about a mile southwest of Brule near the ranger station and Copper Range about four miles north of town, neither with electricity.
The 2026-2027 trout guide lists the County S to County B section separately. It opens May 2 at 5 a.m. and closes September 30, only artificial lures may be used, and the daily bag is 3 trout and salmon in total, of which only 2 may be brown trout and only 1 a rainbow. Length limits are 10 inches for brook trout, 15 for browns, 12 for salmon and 26 for rainbows. Everything else above Highway 2 that is not covered by that listing falls under the Lake Superior stream base rule: May 2 through September 30, 5 trout and salmon, only 2 browns over 15 inches, only 1 rainbow, with minimums of 8 inches for brook trout, 10 for browns, 12 for salmon and 26 for rainbows.
The run calendar below the highway
The DNR's catch calendar is the thing to print. Spring steelhead start in late March, and the first fish caught are usually the ones that overwintered from the previous fall; bright lake fish show in April and continue into early May, with water temperature deciding the peak. Lake-run browns enter from early July through late October and peak from mid-July to mid-September, fished in the slow, deep holes in low light. A smaller run of Chinook comes in from early July to mid-October, peaking mid-August to late September. Coho move from late August to late November with the peak in September. Fall steelhead begin in mid-August and run through late November, with the heaviest movement somewhere between mid-September and late October depending on flow and temperature.
Balcerzak writes that 60 to 80 percent of the annual run is in the river by mid to late October and spends the winter there, which is why opening weekend in March is fished by anglers who know the fish are already holding near spawning gravel. Jason Swingen of JS-Outdoors fishes a size 6 to 10 stonefly as the point fly with a smaller jig nymph or egg on the dropper.
Box Car Hole, Mays Ledges and the lamprey barrier
Below US 2 the river opens March 28, 2026 and stays open through November 15, with no bait restriction. Two things close parts of it. Night fishing is prohibited from a half hour after sunset to a half hour before sunrise from March 28 through May 1 and again from October 1 through November 15. And three refuges are posted: the area known as Box Car Hole is closed July 15 through October 31, the area known as Mays Ledges is closed September 1 through May 31, and the sea lamprey barrier refuge, 500 feet upstream and downstream of the barrier, is never open. The DNR's tributary FAQ adds that there is no early catch-and-release trout season on any Lake Superior tributary, so the January opener elsewhere in Douglas County does not apply here.
Anglers 16 and older need a Wisconsin fishing license and an inland trout stamp. The river north of Highway 2 has many marked day-use access points through the state forest, and the DNR notes the character changes from one to the next, so moving is easy.
Hendricksons in May, Hex in the dark
The most useful chart for this river is the northern Wisconsin mayfly chart at WiFlyFisher, built for the Brule, Namekagon, Wolf and their neighbors. It puts olives from late March through June and again in September, Hendricksons in the last half of April and first half of May, Sulphurs in late May into early June, March Browns and Gray Fox from late May through most of June, Brown Drakes in June, Hex from mid June into early July, Isonychia from late June through August, Tricos in July and the White Fly in August. Superior Fly Angler simply calls the upper river's Hex fabled, and FlyFishFinder's Wisconsin chart puts it in late June and July with the Brule among the rivers that produce.
What the Brule gauge is telling you
USGS 04025500 sits at the town of Brule near the highway, so it reads the spring creek's outflow before the steep lower river adds its tributaries. The record goes back to 1942 and it is a remarkably steady river: monthly means run about 135 cfs in January, 156 in March, 276 in April, 234 in May, 191 in June, 163 in July, 149 in August, 154 in September and 160 in October. Swingen's report from a cold April describes 140 to 160 cfs as low and clear, with steelhead pulled out of the riffles and stacked in the deeper, slower pools. No shop publishes a wading band, so the 120 to 250 cfs range on this page is built from that report and the USGS record: below it the fish are concentrated and spooky, above about 250 you are into snowmelt or a fall rain and the lower river's fast water becomes hard to wade safely.