Osage Co State Fishing Lake
Osage County, KansasView mapDirections
Clarity, phosphorus, and algae all sit in the cleanest band for this region.
↑ up from B at the last regrade
- Mesotrophic
- #1 of 5 in the county
- 42 ft max depth
- Public access
- Limited data
Osage Co State Fishing Lake in Osage County, Kansas has a water quality grade of A (Excellent). Water clarity: 6.2 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 6 µg/L.
- Clarity
- 6.2 ft
- Max depth
- ~42 ft est.
- Type
- Mesotrophic
- Phosphorus
- 20 µg/L
- Chlorophyll-a
- 6 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
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Watch Osage Co State Fishing Lake’s letter
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Osage Co State Fishing Lake is a mesotrophic lake in Osage County, Kansas with an estimated average depth of about 42 feet. Water quality is graded A based on 2 sampling years through 2017. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 4 other monitored lakes in Osage County, Osage Co State Fishing Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, KDHE, last sampled 2017-08-02. Grade methodology: LakeQuality methodology.
Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
The A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
Water Quality Grade: A (Excellent)
Murky, only visible to about 6.2 ft. Phosphorus 20 µg/L. Chlorophyll-a 6 µg/L. TSI 49. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.2 ft | Not graded |
| Phosphorus | 20 µg/L | Good |
| Chlorophyll-a (Algae) | 6 µg/L | Good |
| Trophic State Index (TSI) | 49 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~42 ft est. |
| Average Depth | ~11 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Kansas has not published bathymetry for Osage Co State Fishing Lake.
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Fishing Osage Co State Fishing Lake
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.1 m/yr | 2 |
| Phosphorus | → Stable | 0 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +0.15 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Osage Co State Fishing Lake is a man-made reservoir impounded by the Osage State Fishing Lake (completed 1955) on the One Hundred-Ten Mile Creek-Tr, 49 ft tall and 1,120 ft long.
- Normal storage
- 2,085 ac-ft
- Max storage
- 2,533 ac-ft
- Hazard class
- Low
- Owner
- KANSAS DEPT OF WILDLIFE PARKS & TOURISM
Source: USACE National Inventory of Dams, NID ID KS00888 · Operator website · Matched by proximity (0.21 km)
County Ranking
Ranked #1 of 5 lakes in Osage County
Nearby Lakes in Osage County
Frequently asked questions about Osage Co State Fishing Lake
Where is Osage Co State Fishing Lake?
- Osage Co State Fishing Lake is a lake in Osage County, Kansas. LakeQuality grades it A for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Osage Co State Fishing Lake?
- Osage Co State Fishing Lake in Osage County, Kansas has a water quality grade of A (Excellent). Water clarity: 6.2 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 6 µg/L.
Is Osage Co State Fishing Lake safe to swim in?
- The A is nutrients and algae, not a swimming clearance. Check local advisories before you swim.
How deep is Osage Co State Fishing Lake?
- No published bathymetric survey covers Osage Co State Fishing Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 42 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Explore Osage Co State Fishing Lake across LakeQuality
More Kansas Lake Rankings
Other Grade A Lakes in Kansas
Mesotrophic Lakes in Kansas
Where this data comes from
10 measurements from 1 monitoring station, 2013–2017. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Kansas Department Of Health And Environment
21KAN001_WQX10 samples · 2013–2017
Analytical methods
- Depth, Secchi disk depth
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Lake size & watershed from HydroLAKES (HydroSHEDS)