Post-spawn bass active at Grand River mouth as summer salmon approach

What's Biting

What's Next

With the Grand River at 3,260 cfs and the full moon peaking June 1, the next 48 to 72 hours set up as a prime window for post-spawn smallmouth bass along current breaks and gravel points at the river mouth. Full moons typically push baitfish shallow and trigger aggressive feeding in low-light conditions; target the first and last hours of daylight where river current meets open lake water. Tactical Bassin notes that post-spawn bass are keying on isolated offshore structure right now — drift outside flats, cast to visual cover, and let wind work the presentation. Chatterbaits and swimbaits drew reaction strikes in their recent on-water sessions, while dropshot and neko rigs cleaned up on pressured fish.

Chinook and coho salmon are a growing story for this stretch. Per the WI DNR Lake Michigan Fishing Report, the 2024 alewife forage class was exceptionally strong, driving record coho and near-record Chinook numbers last season — year classes that are now maturing and beginning their early-summer staging near lake tributaries. Kings typically begin concentrating near river mouths in late May and early June, often holding 20 to 40 feet down along current edges where cold, oxygenated river water meets warmer lake surface. Spoons, stickbaits, and flasher-fly combinations trolled near the thermocline will be the go-to approach as this pattern develops through the month.

Steelhead activity at the mouth is winding down as the season transitions. Any fish encountered now will be drop-backs — lake-bound fish beginning to recover from the spawn. Unless a sharp cold snap reactivates the run, expect steelhead counts to fall quickly through the coming week.

Walleye are worth targeting in early-morning low-light periods along the river mouth current seams. No specific Grand River walleye report appeared in available sources this week, but early June is typically consistent for walleye at tributary mouths across the Great Lakes region — jigs tipped with soft plastics or live rigs worked along structure-rich bottom cover the zone well. Check local forecasts before launching; late May and early June on Lake Michigan can produce fast-moving fronts that build significant chop on the open water with little notice.

Context

Early June at the Grand River mouth is historically one of the most dynamic transitions on the western Michigan fishing calendar. The spring steelhead run, which peaks in March and April, fully unwinds by early June, and the summer salmon season begins in earnest — typically within the next two to three weeks as lake surface temperatures warm and Chinook begin pushing from deep summer holding water toward their fall tributaries.

The WI DNR Lake Michigan Fishing Report offers the clearest cross-lake context for how the season is shaping up. The 2024 harvest was exceptional: record coho numbers (over 210,000) and the highest Chinook tally since 2012 (over 160,000), both driven by strong alewife forage classes in recent years. That same forage base supports 2026 salmon survival and growth, lending well-grounded optimism to the approaching summer season on both sides of the lake.

Grand River flow at 3,260 cfs per USGS gauge 04119000 sits in a typical range for late May in a non-flood year. Flows commonly run elevated through May as snowmelt and spring rains drain the watershed; by late June they usually settle below 2,000 cfs, clearing near-mouth visibility and improving conditions for salmon and bass anglers. Nothing in the current reading suggests an anomaly.

For bass, early June consistently delivers some of the best fishing of the year on this water. Post-spawn fish transition off shallow nesting areas and begin feeding aggressively, and the full moon accelerates the shift toward open-water summer patterns. Jason Mitchell Outdoors has been tracking shallow spring smallmouth across the upper Midwest through May, noting fish actively responding to post-spawn presentations — a pattern that applies directly to the Grand River mouth gravel and rock structure entering June.