Post-spawn bass and spring coho headline mid-May at the Grand River mouth

What's Biting

What's Next

No weather forecast data was included in this report's environmental feed — check Weather.gov for Grand Haven or Muskegon before heading out, as spring conditions on Lake Michigan can shift quickly and wind direction matters for both coho staging and smallmouth positioning.

At 4,010 cfs, the Grand River is running above its typical late-May base but within the range that keeps the river mouth fishable. If flows ease over the next few days — as snowmelt contributions taper off — clarity should improve at the Grand Haven outlet, sharpening conditions for coho staging along the current seam where river water meets the colder lake. Elevated, stained flows favor darker and more vibrant lure profiles; transition to natural silver and chartreuse presentations as color improves with dropping levels.

The new moon on May 17 anchors the strongest low-light feeding window of this lunar cycle. Dawn through about 8 a.m. and the final 90 minutes before sunset are your best windows over the next three to four days. Post-spawn smallmouth are especially responsive during these windows. Fishing the Midwest highlights shallow-water casting approaches as reliably productive in early spring across the region — rocky points, sand-and-gravel flats, and any nearshore structure holding baitfish are worth prioritizing at first and last light.

On The Water notes that windy conditions push big smallmouth onto the feed along Great Lakes structure — watch the forecast for afternoons with a steady 10–15 mph onshore blow, which can activate bass along the Lake Michigan shoreline and the river mouth jetties.

Spring coho staging near the Grand Haven mouth are worth targeting through late May and into early June. The record 2024 class documented by WI DNR Lake Michigan Fishing Report suggests above-average numbers cycling through the system. Inline spinners, spoons, and spin-glo rigs worked along the current seam at dawn are traditional producers. Watch for diving birds over the mouth — they frequently telegraph baitfish pushes that coho are actively keying on.

For walleye, the post-spawn transition typically shifts fish from shallow gravel to mid-depth channel bends. Jig-and-minnow presentations worked along the slower inside edges of the lower Grand's deeper runs are worth a look as water temperatures climb toward the upper 50s°F.

Context

Mid-May on the Grand River and Lake Michigan's eastern shore marks one of the more dynamic transition weeks of the Great Lakes fishing calendar. The steelhead run — which peaks in western Michigan tributaries from late March through mid-April — is typically winding toward its close by the third week of May, with only late-run stragglers holding in deeper, oxygenated pools. Historically, this is when the focus shifts: post-spawn smallmouth move into feeding mode, walleye spread across mid-depth structure, and the spring coho window that runs roughly late April through June at Lake Michigan tributaries opens fully.

The 2024 lake-wide harvest numbers reported by WI DNR Lake Michigan Fishing Report are meaningful long-range context: record coho (210,000-plus) and the highest Chinook tally since 2012 both point to a healthy alewife forage base and well-managed stocking programs. Those 2024 coho year-classes are now two-year fish approaching peak catchable size — adding to the nearshore and tributary population available to anglers this spring.

At 4,010 cfs, the Grand River's current flow is elevated compared to typical late-May base levels, which historically settle in the 2,000–3,000 cfs range at this gauge by mid-to-late May. The higher reading likely reflects recent rain or lingering snowmelt contributions from inland. Slightly elevated flows at this point in the season are not unusual and generally do not shut down fishing — they push fish toward slower side-channel edges, pool tails, and seams where they can intercept food without fighting heavy current.

No water temperature reading was available from USGS gauge 04119000 or a nearby Lake Michigan buoy in this report cycle, making it difficult to pinpoint precisely where temperature-sensitive species sit on the seasonal curve. Typical Lake Michigan nearshore surface temperatures in mid-May range from the upper 40s to the low-to-mid 50s°F on the eastern shoreline. No direct year-over-year comparison data from current 2026 state agency reports was available in this pull to assess whether the season is running early, late, or on schedule.