I did some research and compiled a list 3-Gun matches in SE Michigan.
Here is what I found:
Brooklyn Sportsman’s Club
https://www.brooklynsportsmansclub.com/
Sunday
4/22
5/27
6/24
7/22
8/26
9/23
10/28
Livingston Gun Club
http://www.livingstongunclub.org
Sunday
3/18 intro class
4/15
5/27
6/17
7/15
8/26
9/16 Championship Match
Michigan 3-Gun Combat @ Blue Water Sportsman’s Club
http://www.michigan3guncombat.com/
Saturday
3/24
4/21
5/19
6/16
7/14
7/28 Shotgun Only
9/15
10/13
11/10
Livingston Conservation & Sports Association
http://www.lcsa.info/
Saturday
4/28
5/26
6/23
7/28
Black Rifle Action Shooting Society
http://www.carobrass.net/events.html
Saturday
3/10
4/14 (Tactical Timmy 2 Gun)
5/12
6/9
7/14 (Trident 3 Man 3 Gun Match)
Linwood Bay Sportsman’s Club 3-Gun (Munger)
http://linwoodbaysportsmans.com/
Sunday
4/8
6/3
7/1
8/5
9/30 - Championship