Ruth Lake
Crow Wing County, Minnesota599 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Ruth Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- 2 aquatic invasives
- 39 ft max depth
- Public access
Ruth Lake in Crow Wing County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 16 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.7 µg/L. Maximum depth: 39 ft. Surface area: 599.2 acres.
Minnesota DNR's Targeted Survey on July 6, 2022 caught 1.09 northern pike per hour of electrofishing at Ruth Lake. DNR survey details →
Ruth Lake is a 599-acre cold, clear oligotrophic lake in Crow Wing County, Minnesota with a maximum depth of 39 feet. Overall water quality is improving over recent sampling years. The lake supports 12 documented fish species including black crappie, bluegill, and hybrid sunfish. Public access is available with 1 public boat landing. Compared to the 84 other monitored lakes in Crow Wing County, Ruth Lake ranks #60 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-14. Methodology: how these readings are compared.
Ruth Lake covers about 600 acres in Crow Wing County. It has one public boat landing. The median ice-out date is April 26, which is when the open-water season begins. For a place on the water, look through cabin and lake-house rentals near Ruth Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Ruth Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16 ft of visibility
- Boat launch1 documented ramp
- Fishing12 species recorded
- Ice seasonIce-out around Apr 26
- Deep water39 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Ruth Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
Whether Ruth Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Ruth Lake
These are the measurements Minnesota PCA publishes for Ruth Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Crystal clear, you can see 16 ft down. Phosphorus 11 µg/L. Chlorophyll-a 2.7 µg/L. TSI 39.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 16ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 11µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.7µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 39 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Ruth Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Ruth Lake typically sits around 67°F at the surface in September. Summer average is about 71°F. Usually warmest in Jul (about 74°F) and coldest in May (about 56°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (56°F) to its warmest (74°F).
Typical surface water temperature by month, from 27 field readings (2017–2025) via the EPA Water Quality Portal. See the full Ruth Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on July 6, 2022 caught 1.09 northern pike per hour of electrofishing at Ruth Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ruth Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2022-07-06 (Targeted Survey).
8 surveys on file · most recent 2022-07-06 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 42.24 | 2–9 in 2021-06-07 | 0.14 lb |
| Largemouth Bass | 30.36 | 6–18 in 2021-06-07 | 0.87 lb |
| Yellow Bullhead | 26.17 | 7–13 in 2021-06-07 | 0.58 lb |
| Bluntnose Minnow | 8.59 | ||
| Yellow Perch | 6.75 | 5–9 in 2021-06-07 | 0.24 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Bluegill
Largemouth Bass
Yellow Bullhead
Yellow Perch
From the 2022-07-06 survey
A targeted survey of nearshore fish species in Ruth Lake was conducted on July 6-7, 2022, by Index of Biological Integrity (IBI) Program staff. Sampling sites were evenly spaced around the lake, and each was sampled by backpack electrofishing and seining with a 50-foot or 15-foot seine, where possible. Backpack…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Ruth Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — RuthFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Ruth (0233)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — RuthFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — RuthPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
39 ft
Surface area
599 acres
Shoreline
5.1 mi
Littoral zone
33%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
4 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,260 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Ruth LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Ruth Lake
Compare lakeside cabins, hotels, and vacation rentals near Ruth Lake in Crow Wing County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Ruth Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Ruth Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Ruth Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-0.84 µg/L/yr6 years
Chlorophyll-a
Improving-1.03 µg/L/yr6 years
Ice season
Typical ice-out
Apr 26
Earliest Apr 12, 2015 · Latest May 13, 2013
Most recent ice-out
May 2
2018
7 observations · Minnesota PCA ice records
EPA Impairment Status
Ruth Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN18-0212-00 · Official waterbody report
Nearby Lakes in Crow Wing County
Frequently asked questions about Ruth Lake
Where is Ruth Lake?
- Ruth Lake is a lake in Crow Wing County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Ruth Lake?
- Ruth Lake in Crow Wing County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 16 ft visibility. Phosphorus: 11 µg/L. Chlorophyll-a (algae): 2.7 µg/L. Maximum depth: 39 ft. Surface area: 599.2 acres.
Is Ruth Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Ruth Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury. Check local advisories before you swim.
What is the water temperature of Ruth Lake?
- Ruth Lake typically sits around 67°F at the surface in September, from 27 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is Ruth Lake?
- Ruth Lake has a maximum depth of 39 feet. The lake covers 599.2 acres.
What fish are in Ruth Lake?
- Fish species found in Ruth Lake include black crappie, bluegill, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, smallmouth bass, walleye, white sucker, yellow bullhead, yellow perch. Ruth Lake is located in Crow Wing County, Minnesota.
What did the DNR fisheries survey find at Ruth Lake?
- Minnesota DNR's Targeted Survey on July 6, 2022 caught 1.09 northern pike per hour of electrofishing at Ruth Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ruth Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Ruth Lake thaw?
- Ruth Lake typically has ice-out around Apr 26.
Are there boat ramps on Ruth Lake?
- Ruth Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ruth Lake. Public access is listed as yes.
Can I fish at Ruth Lake?
- Ruth Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
Explore Ruth Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Crow Wing County
Species activity outlook by water temperature and season
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Top lakes and where to stay in the Mille Lacs Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Pine River Watersheds (Brainerd Lakes), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Compare Ruth Lake With Nearby Lakes
Where this data comes from
81 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA81 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate