Oasis Ranch Upper Lake
Audrain County, MissouriView mapDirections
Missouri DNR publishes the water-quality measurements for Oasis Ranch Upper Lake. Here is what has been measured.
- Oligotrophic
- Limited data
Oasis Ranch Upper Lake in Audrain County, Missouri has water-quality measurements published by Missouri DNR, shown here as reported. Water clarity: 14.4 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 1.8 µg/L.
Oasis Ranch Upper Lake is a cold, clear oligotrophic lake in Audrain County, Missouri. Compared to the 2 other monitored lakes in Audrain County, Oasis Ranch Upper Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Missouri DNR, last sampled 2024-09-18. Methodology: how these readings are compared.
What Oasis Ranch Upper Lake is good for
From access and monitoring records, not editorial picks.
- Clear water14.4 ft of visibility
Swimming conditions
Readings onlyLimited data
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. Check local advisories before you swim.
Whether Oasis Ranch Upper Lake is safe to swim in today is a call for the Missouri Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Oasis Ranch Upper Lake
These are the measurements Missouri DNR publishes for Oasis Ranch Upper Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 14.4 ft. Phosphorus 12 µg/L. Chlorophyll-a 1.8 µg/L. TSI 38.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 14.4ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 12µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.8µg/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. | 38 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Oasis Ranch Upper Lake
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Fishing Oasis Ranch Upper Lake
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Oasis Ranch Upper Lake under Clean Water Act (NPDES) discharge permits.
- Monroe County Pwsd 2 - Rush Hill WwtfRush Hill · 2.9 mi away · NPDES MO0126888
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Nearby Lakes in Audrain County
Frequently asked questions about Oasis Ranch Upper Lake
Where is Oasis Ranch Upper Lake?
- Oasis Ranch Upper Lake is a lake in Audrain County, Missouri. Its water-quality measurements are published by Missouri DNR and shown on this page as reported.
What is the water quality of Oasis Ranch Upper Lake?
- Oasis Ranch Upper Lake in Audrain County, Missouri has water-quality measurements published by Missouri DNR, shown here as reported. Water clarity: 14.4 ft visibility. Phosphorus: 12 µg/L. Chlorophyll-a (algae): 1.8 µg/L.
Is Oasis Ranch Upper Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Explore Oasis Ranch Upper Lake across LakeQuality
More lakes in Missouri
Other Lakes in Missouri
Oligotrophic Lakes in Missouri
Where this data comes from
17 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Univ. of Missouri, Columbia
UMC17 samples · 2024
Analytical methods
- Depth, Secchi disk in meters
- 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
- 445.0 ~ EPA; Chlorophyll and Pheophytin in Algae by Fluorescence
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)