Big Portage (E Bay Lake

Big Portage (E Bay Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. Clarity is the limiting factor — phosphorus is reasonable but suspended particles or algal cells keep water transparency below Minnesota norms.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. The lake bottoms out at 23 ft — a moderate depth that supports a warm-water fishery without the year-round cold refuge a deeper basin provides. The lake's 902 acres and 7.2 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Big Portage (E Bay Lake sits at rank 98 of 132 in Cass County, in the lower half of the local distribution.

Big Portage (E Bay Lake has no invasive species recorded in Minnesota state databases as of 2025, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 13 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.