The riverway, the state line and whose rules you follow
The National Park Service runs the St. Croix National Scenic Riverway, 255 miles of the St. Croix and Namekagon, and its fishing page settles the question everyone asks. The state boundary begins about 2.5 miles downstream of Riverside Landing; upstream of that the St. Croix is entirely in Wisconsin. Where it is a border, a Minnesota or Wisconsin license is good from shore to shore, Minnesota residents must carry a Minnesota license and Wisconsin residents a Wisconsin one, residents of other states may hold either, and you must have a copy of the license with the fishing endorsement on you because a driver's license is not accepted. You follow the regulations of the state in which you are fishing, not the state that sold you the license, and when you land a boat you are checked by the state you land in, which is worth thinking about when you pick a ramp.
Two more federal-zone rules: live crayfish may not be used as bait on the Riverway, and the Park Service asks that no live bait ever be dumped in the river. The Park Service describes the Danbury-to-Indianhead Flowage reach north of St. Croix Falls as smallmouth water and everything below Taylors Falls as a warmwater mix of bass, walleye, sauger, pike, muskellunge, catfish, sturgeon and panfish.
Taylors Falls to Stillwater, ramp by ramp
The Minnesota DNR's East Metro office assesses the river from the Dalles below the Highway 8 bridge down to the lift bridge at Stillwater, and its species notes are candid: smallmouth bass higher than average in abundance with all sizes, walleye and sauger average, catfish higher than average with record-size fish, lake sturgeon higher than average, muskellunge average, pike low, and more than 60 species documented including paddlefish and American eel. Its comment is that walleye, sauger and smallmouth are what people fish for here, that access and shallow water limit bigger boats, and that sandbars and debris make running the river hard at normal or low water.
Ramps from the top: Interstate Park on Highway 95 south of Taylors Falls, with a fee; Franconia Landing at the end of Franconia Trail, small and shallow; Osceola Landing, a Park Service site off Highway 243; the Log Cabin access at the end of 205th Street North for cartops and canoes; William O'Brien State Park north of Marine on St. Croix, with a fee; and the DNR's Boom Site north of Stillwater, which fills on summer weekends. Boats may not run from below the Arcola sandbar to above it, Park Service staff are posted at the bar to stop them, and most of the water above the Soo Line high bridge is slow-no-wake. For shore fishing the DNR names Interstate Park, the Osceola picnic area, O'Brien's lower campground and the outfall below Lake Alice, the stairs at the Boom Site wayside, and the retaining wall in Stillwater's park between the lift bridge and the marina.
Closed from the dam to the Highway 8 bridge, March 2 to June 15
Minnesota's 2026 border-water pages list a fish sanctuary on the St. Croix from the Taylors Falls dam down to the upstream side of the Highway 8 bridge, closed to all fishing by bank or boat from March 2 through June 15. That is the spring walleye and sturgeon water, and it is off limits in the spring. Everywhere else the border table applies, and it splits at the dam. Downstream of the dam to the US 10 bridge at Prescott, walleye and sauger are open May 2, 2026 through March 1, 2027 with four combined, a 15-inch walleye minimum and only one walleye or sauger over 20 inches. Upstream of the dam the bag is six combined with the same minimum.
Largemouth and smallmouth below the dam are open May 23, 2026 through March 1, 2027, five at 14 inches; above the dam the harvest season ends September 13 and the bass are catch and release from September 14 through March 1. Northern pike below the dam are three, one of them over 30 inches at most. The muskellunge season is May 23 to November 30, one fish, 50-inch minimum. Channel catfish below the dam are five with one over 24 inches, flathead two with one over 24 from April 1 through November 30. Border-water anglers may run two lines, one bait each, and a fish hooked anywhere except the mouth is released.
Sturgeon: one fish a year, in September, with a tag
Lake sturgeon are what make the Stillwater reach unusual, and the DNR is monitoring tagged sturgeon here along with tagged catfish. From the Taylors Falls dam down to the mouth, including Lake St. Croix, sturgeon are catch and release from June 16 through September 4, then from September 5 through September 30 one fish per calendar year may be kept at a 60-inch minimum with a sturgeon tag or endorsement, then catch and release again from October 1 through March 1. Above the dam it is catch and release from June 16 through March 1 with no tag needed. Shovelnose sturgeon on the St. Croix and Lake St. Croix are catch and release from June 16 through March 1.
The DNR's management notes for the reach include stocking a thousand surplus muskellunge fingerlings when they are available and watching for invasive carp, which have been found from Taylors Falls down to the Mississippi. Zebra mussels are in the river below the Arcola sandbar and milfoil throughout, so drain and clean before you leave.
What the Stillwater gauge measures, and when the river fishes
USGS 05341550 is at Stillwater, on the lake-like lower river where the St. Croix backs up above Prescott, with 7,060 square miles behind it. It reports discharge for the whole river, Namekagon included, but it sits below the smallmouth water rather than in it; the Wisconsin hub's St. Croix Falls gauge reads the flow coming over the dam at the top of this reach. The Stillwater record is short, 2011 to 2024, and its monthly means run about 3,400 cfs in January, 5,500 in March, 12,100 in April, 10,800 in May, 7,900 in June, 6,100 in July, 4,000 in August, 4,700 in September and 5,700 in October. No shop or guide publishes a fishable range for it, so the 3,000 to 8,000 cfs band here is the June-to-October envelope of that record, the months when the DNR's warning about sandbars and debris at normal and low water is the one that applies. Above 8,000 the river is in spring mode and the sanctuary is closed anyway.
The forage calendar for smallmouth here is the one every Upper Midwest river shares: minnow patterns and crayfish from the late-May opener through October, topwater on summer evenings, and FlyFishFinder's note that crayfish imitations are the St. Croix's most reliable producers. Fall belongs to the muskie anglers working Lake St. Croix and the Hudson water below Stillwater.