Sullivan Lake
Cass County, Minnesota, near Tobique. DNR lake ID 11008500.
Sullivan Lake is a 42.1-acre lake in Cass County, Minnesota, near Tobique. Its deepest point reaches 50 ft, and about 33% of the lake is shallower than 15 feet. Summer water clarity averages 10.6 feet in Minnesota Pollution Control Agency monitoring. It is not on the DNR infested waters list as of September 2026.
Buying or selling on Sullivan Lake? Ask us what lakeshore here actually sells for, which stretches of shoreline buyers compete for, and what’s coming up before it’s listed.
Tell us about your dream home on Sullivan LakeWhat’s my Sullivan Lake property worth?Call (218) 656-6469
Quick facts
| DNR lake ID | 11008500 |
|---|---|
| County | Cass County, near Tobique |
| Surface area | 42.1 acres |
| Maximum depth | 50 ft |
| Share under 15 ft | 33% |
| Water clarity (summer) | 10.6 ft through 2025 (satellite estimate) |
| Invasive species | Not on DNR infested waters list (Sept 2026) |
| Public water accesses | 0 |
Water quality
Summer averages from Minnesota Pollution Control Agency monitoring through 2025: clarity 10.6 ft.
Fishing on Sullivan Lake
The most recent DNR standard fish survey was in 1986 (40 years ago). Catch per net is compared with the DNR’s typical range for lakes of the same type.
| Species | Net | Catch per net | Typical range |
|---|---|---|---|
| Northern pike | gill | 2.5 | 2.0 to 8.0 |
| Yellow perch | gill | 6.0 | 1.5 to 18.5 |
| Bluegill | gill | 31.0 | n/a |
| Largemouth bass | gill | 1.0 | 0.5 to 1.7 |
Fishing regulations
No lake-specific regulation found in Minnesota Rules or the DNR sunfish list. Statewide and zone regulations apply.
Regulations change. Confirm with the DNR before fishing.
Invasive species
Not on the Minnesota DNR infested waters list as of September 2026. That means no confirmed listing, not a guarantee the lake is free of invasive species.
Public boat access
No public water access on DNR record.
Nearby lakes
- Tidd Lake 1.4 mi, Cass County
- Cedar Lake 1.5 mi, Cass County
- Grave Lake 2.0 mi, Cass County
- Lower Milton Lake 2.1 mi, Cass County
- Upper Milton Lake 2.2 mi, Cass County
- Little Sand Lake 3.1 mi, Cass County
- Knight Lake 3.5 mi, Cass County
- Wilson Lake 4.0 mi, Cass County
Questions about Sullivan Lake
How deep is Sullivan Lake?
Sullivan Lake reaches a maximum depth of 50 ft according to Minnesota DNR records. About 33% of the lake is shallower than 15 feet.
How big is Sullivan Lake?
Sullivan Lake covers about 42.1 acres in Cass County, Minnesota.
How clear is Sullivan Lake?
Summer water clarity on Sullivan Lake averages 10.6 feet (Secchi depth) in MPCA monitoring through 2025.
Does Sullivan Lake have zebra mussels or other invasive species?
Sullivan Lake is not on the Minnesota DNR infested waters list as of September 2026. That means there is no confirmed listing; it is not a guarantee the lake is free of invasive species.
Are there lake homes for sale on Sullivan Lake?
Homes on Sullivan Lake come up for sale throughout the year, and some sell before they’re ever publicly advertised. Tell us what you’re looking for and our agents will run a custom search and send you matching homes on Sullivan Lake and nearby lakes, including off-market opportunities when available.
What is it like to live on Sullivan Lake?
Small, quiet water suited to paddling and fishing, about 33% shallow shoreline under 15 feet, and summer clarity around 10.6 feet. Conditions vary by property, so walk the frontage and ask us what similar homes have sold for.
Are there special fishing regulations on Sullivan Lake?
No lake-specific regulation was found for Sullivan Lake in Minnesota Rules or the DNR sunfish list. Statewide and zone regulations apply.
Ask us about Sullivan Lake
Whether you’re buying, selling, or just curious, our team works Cass County lakes every day. Send us a note or call (218) 656-6469.
Sources: Minnesota DNR LakeFinder records, DNR fish surveys (latest 1986), DNR infested waters list (Sept 2026), Minnesota Rules 6264.0400 (April 2026), MPCA monitoring via the Water Quality Portal, DNR water access records (2023), LAGOS-US. Lakewide information from public data; it does not describe any specific property. Verify shoreline, bottom type, and depth at any frontage.