Branch County · Michigan

Union Lake

Soundings in feet · 544 acres · deepest 16 ft

Today on the lake

Updated 9 Oct 2026, 3:34 am EDT. Get alerts for Union Lake

WEATHEROvernight: mostly clear, 42°F, wind 0 mph. Friday: mostly sunny, 70°F, wind S 0 to 5 mph.

WARNINGSNo weather or fire warnings in effect.

FIRENo wildfires or prescribed burns reported within 25 miles.

BURNINGCampfires and debris burning: check today's status with Michigan DNR.

ALGAENo cyanobacteria detected by satellite on 5 Oct 2026, the latest clear-sky image.

LAUNCHESUnion Lake: listed open. Michigan DNR record updated 3 Apr 2026.

National Weather Service; National Interagency Fire Center; U.S. EPA CyAN satellite; Michigan DHHS; Michigan DNR. Weather, warnings, fires and satellite refresh when you open the page (checked at most hourly).

Depth map

8 contours, 3 to 16 ft

034567101216feet

Michigan DNR survey, fetched 7 Oct 2026. Not for navigation.

Size and depth

544 acres · deepest 16 ft (measured) · shoreline about 9.1 mi · clarity about 5 ft

Union Lake is the 3rd largest of the 76 named lakes of 10 acres or more in Branch County. By Michigan DNR survey it is the 20th deepest of the 22 with a measured depth. Its water is clearer than 8 of the other 62 lakes in the county with satellite clarity readings. Its shoreline measures about 9.1 miles along the state outline. About 0% of its area is deeper than 6 ft.

Ranks against Branch County lakes in Michigan hydrography, Michigan DNR lake surveys and Michigan EGLE satellite clarity; shoreline measured from the state outline. How we measure

Getting on the water

1 public access site on Union Lake.

Union Lake · Open

1 ramp lane · 5 trailer spaces · 2 car spaces · vault toilet · accessible restroom · Recreation Passport required

Local boating rules, Branch County

Michigan DNR boating access, fetched 7 Oct 2026.

Fishing

Michigan DNR has stocked Union Lake 60 times since 1979. The most recent stocking was 26,176 walleye on 7 June 2022. Species stocked: bluegill, channel catfish, largemouth bass, northern pike, redear sunfish, tiger muskellunge, walleye.

60 stockings, 1979 to 2022, log scale

Latest: 7 Jun 2022: 26,176 walleye.

7 Jun 2022STOCKED26,176 walleye

31 May 2018STOCKED26,314 walleye

26 May 2016STOCKED1,000 walleye

29 May 2015STOCKED19,877 walleye

29 May 2015STOCKED750 walleye

10 Jun 2014STOCKED500 walleye

Source: Michigan DNR Fisheries, fetched 7 Oct 2026. How we measure

Where the deep water is

Show water deeper than

Measured from Michigan DNR contours. How we measure

Water quality

Average water clarity is about 5 ft (Secchi depth 1.5 m, satellite readings 2018–23).

Clarity 4.8 ft of 16 ft

Michigan EGLE satellite clarity, fetched 7 Oct 2026.

Email me about Union LakeWhen it is stockedMichigan DNR has stocked Union Lake 60 times since 1979, most recently 26,176 walleye on 7 June 2022. None so far in 2026.When algae is reported or testedMichigan DHHS has no records for this lake yet. We email when the first one is posted.When satellite sees a bloom startEPA satellite, checked daily, June to October. We email when a bloom first shows on two clear days, not every day it stays. It has not happened in 2026.Any lake in Branch CountyStockings and algae records on every lake in the county. In 2026 so far: 5 emails.

Union Lake has had no stockings or algae records in 2026, so its own alerts would have sent nothing this year. The county alert is on by default.

Email address

At most one email a week per lake. We email you a link to confirm before any alert is sent; every email has a one-click unsubscribe.

Nearby lakes with measured depth

Oliverda Lake35 ft deep · 3.5 mi · Branch County

Kenyon Lake29 ft deep · 3.5 mi · Branch County

Turtle Lake20 ft deep · 5.0 mi · Calhoun County

Goodrich Lake37 ft deep · 6.5 mi · County

Havens Lake20 ft deep · 7.0 mi · St. Joseph County

Morrison Lake50 ft deep · 8.8 mi · Branch County

Michigan DNR survey; straight-line miles.

Common questions

How deep is Union Lake?

Union Lake is 16 feet at its deepest point, measured by Michigan DNR survey. It covers 544 acres.

Is there a public boat launch on Union Lake?

Yes. 1 public access site is listed: Union Lake.

Is Union Lake stocked with fish?

Yes. Michigan DNR has stocked it 60 times since 1979, most recently 26,176 walleye on 7 June 2022.

How much of Union Lake is deeper than 10 feet?

About 17% of the lake's area is deeper than 10 feet, measured from Michigan DNR depth contours.