Bluff country the glaciers missed
The Upper Iowa starts in Mower County, Minnesota, dips into Iowa and runs 156 miles through Howard, Winneshiek and Allamakee counties to the Mississippi near New Albin. It sits in the Driftless Area, which the last ice sheet skipped, so instead of flattened till you get limestone bluffs and steep side canyons. It is also the only Iowa river ever considered for National Wild and Scenic status; a 1971 Park Service study recommended the state protect it first, and the designation never happened, partly because so much of the bank is private.
For planning, Iowa DNR splits it at Decorah. Above town is 79 miles of river with a popular access at Kendallville Park and Campground off Highway 139, about 8 miles northeast of Cresco. Below Decorah is another 57 miles, with a popular access at Lower Dam about 11 miles northeast of town. Many paddlers put in at Kendallville or just below, though some start upstream at Lime Springs.
Three bass, 12 inches, and none through Decorah
Iowa treats the Upper Iowa as an interior stream: black bass are open all year, three a day and six in possession, largemouth, smallmouth and spotted combined, 12-inch minimum. One reach is catch and release only: in Winneshiek County, from the Fifth Street bridge in Decorah downstream as posted to the upper dam, every bass must be released alive right away. Trotlines are legal on the Upper Iowa only from the mouth up to the first dam upstream in Winneshiek County, with no more than five lines and 15 hooks total.
Iowa DNR's smallmouth advice fits this river. The fish spread out and hold behind boulders, snags and undercut banks during high spring flows, move toward spawning gravel in mid to late April, and after the spawn scatter over rocky cover in two feet of water or more. As summer levels drop they bunch up in deeper pockets below riffles and along cut banks, which makes July and August the most predictable wading of the year.
The trout are in the side valleys
The main river is warm-water, but the creeks that cut through the bluffs are spring-fed trout streams, and several enter the Upper Iowa or run close to it. Iowa DNR lists Coldwater Creek, 3 miles northwest of Bluffton, with 4 miles of water; Trout Run on the south side of Decorah; Twin Springs and Dunning's Spring inside Decorah's city parks; North and South Bear creeks around Highlandville; Canoe, West Canoe and North Canoe creeks north of town; and Waterloo Creek, 10.5 miles of it, through Dorchester in Allamakee County. The Chuck Gipp Decorah hatchery, one of the three northeast Iowa trout hatcheries, is in town and open to visitors.
Iowa counts 48 catchable-stocked rainbow trout waters, more than 50 self-sustaining wild trout streams and 10 special-regulation fisheries in the northeast. Announced stream stockings run April through September. You need the Trout Fee on top of a license to fish for or keep trout; the limit is five a day and ten in possession, all species combined, and the season is continuous.
What Decorah reads, and when to float
No outfitter publishes a wading range for the Decorah gauge, so the 200 to 600 cfs band here comes from the USGS record there. Monthly means are around 700 cfs in March and April, 590 in May, 690 in June, then about 350 to 370 cfs in August and September and 313 in October, with winter lows near 160. Inside the band the riffles are wadeable and a canoe floats most of them; well above it the river turns brown fast. Iowa DNR notes that the big watersheds on northeast Iowa smallmouth rivers muddy quickly after heavy rain, and recommends spinnerbaits or rattling crankbaits in chartreuse, brown or black when visibility drops below 6 inches.
September 2026 showed how quickly that happens: in the three weeks before the 24th the Decorah gauge ran from 185 cfs up to 5,750 after storms, and it was still near 1,600 cfs on the 24th. In a spell like that, save the day for one of the small spring creeks and come back to the river when Decorah drops under 600.
Smallmouth through the year
Pre-spawn in April and early May, when water is in the 40s and 50s, brings the biggest fish shallow. Summer is crayfish and minnows along the bottom of the deeper runs, with topwater early and late around boulders and pool edges. Fall, with lower sun and cooler water, pulls larger bass back onto shallow structure again.