My Family and I are headed to Portage lake in onekama in August. Looking for a few tips on where to start. Any help would be much appreciated!

MI DNR has a map of Portage at this site  http://www.dnr.state.mi.us/SPATIALDATALIBRARY/PDF_MAPS/INLAND_LAKE_MAPS/MANISTEE/PORTAGE_LAKE.PDF WhWhen you are there consult any bait shop you can find.

 

I've not fished them but have heard they are good.  Couldn't find a map of Onekama.

 

Also in the area are Lower Herring, which has good walleyes and SMB, good map on line for this one, too.  Rocky areas at and just north of the launch, the inlet is good in the evening, rocky along the reedy south shore, long edge into the deep goes out from the west end of Collins Bay, and smb (and walleyes) hang out along it, on the deep side.  Check out the launch pretty carefully-it used to be too shallow but expect with high water it will be fine.

 

Arcadia Lake goes right into Lake MI and smb at times hang out along the rip rap and around the pier heads.  Inside it gets shallow and weedy straight in, but the area around the launch, and from the launch out, has depth and is good.  LMB are found there, as well as SMB, some of good size.  

I fished it a couple years ago, but during pre-spawn and had a good day.  Started out on the long point on the NW side with tubes and swim baits and caught a dozen SMB, biggest about 4.5#.  I then went east and north around the corner and caught a 5.5# LMB on a Swimbait.  I was targeting SMB so I didn't go to the East side where I was told the larger LMB population is.  A local told me the LMB is becoming the dominant species in numbers over the past few years.