Mckay Lake
Umatilla County, Oregon1,200 acresView mapDirections
Not enough samples to grade — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). No letter yet. Here is what we do have.
- Impaired · Mercury
- Public access
- Limited data
Mckay Lake in Umatilla County, Oregon is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.3 ft visibility. Phosphorus: 121.5 µg/L. Chlorophyll-a (algae): 49.4 µg/L. Surface area: 1200 acres.
- Clarity
- 3.3 ft
- Area
- 1,200 acres
- Phosphorus
- 121.5 µg/L
- Chlorophyll-a
- 49.4 µg/L
- Trend
- ↑ Improving
- Public access
- Yes
Stays via Stay22
Stays near Mckay Lake
Compare lakeside cabins, hotels, and vacation rentals near Mckay Lake in Umatilla County, Oregon — 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 Mckay Lake
Prices for Sep 11–13, 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 trip? Cabins and lodging at Mckay Lake → · more Oregon lake trips
Watch Mckay Lake’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Why Mckay Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mckay Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity, phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by Oregon DEQ and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Mckay Lake is a 1,200-acre lake in Umatilla County, Oregon. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2020-06-15. Grade methodology: LakeQuality methodology.
What Mckay Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Big water1,200 acres
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Mckay Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury). Check local advisories before you swim.
Water quality measurements for Mckay Lake
These readings exist but are not enough for an A–F grade — see why.
Very murky, less than 3.3 ft of visibility. Phosphorus 121.5 µg/L. Chlorophyll-a 49.4 µg/L. TSI 67.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.3 ft | Not graded |
| Phosphorus | 121.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | 49.4 µg/L | Not graded |
| Trophic State Index (TSI) | 67 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 1,200 acres |
| Public Access | Yes |
No bathymetric survey has been published for Mckay Lake, so its depth is not documented here.
Recreation & Access
- McKay Creek (North)Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Mckay Lake
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | ↑ Improving | -8.23 µg/L/yr | 3 |
Reservoir Info (USACE NID)
Mckay Lake is a man-made reservoir impounded by the Mckay Dam (completed 1927), built primarily for flood risk reduction on the Mckay Creek; earth-type dam, 165 ft tall and 2,700 ft long.
- Surface area
- 1,200 ac
- Normal storage
- 67,800 ac-ft
- Max storage
- 71,534 ac-ft
- Drainage area
- 193.24 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Flood Risk Reduction;Irrigation.
Source: USACE National Inventory of Dams, NID ID OR00583 · Operator website
EPA Impairment Status
Mckay Lake is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit OR_LK_1707010304_02_100009 · Official waterbody report
Graded lakes near Mckay Lake
Mckay Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Umatilla County
Frequently asked questions about Mckay Lake
Where is Mckay Lake?
- Mckay Lake is a lake in Umatilla County, Oregon. LakeQuality has not rated this lake (UNRATED) — no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years).
What is the water quality grade for Mckay Lake?
- Mckay Lake in Umatilla County, Oregon is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.3 ft visibility. Phosphorus: 121.5 µg/L. Chlorophyll-a (algae): 49.4 µg/L. Surface area: 1200 acres.
Is Mckay Lake safe to swim in?
- The letter is not a swimming clearance. Mckay Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, metals (other than mercury). Check local advisories before you swim.
Are there boat ramps on Mckay Lake?
- Mckay Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include McKay Creek (North). Public access is listed as yes.
Explore Mckay Lake across LakeQuality
More Oregon Lake Rankings
Other Lakes in Oregon
Eutrophic Lakes in Oregon
Where this data comes from
6 measurements from 1 monitoring station, 2020. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Bureau of Reclamation
1119USBR_WQX6 samples · 2020
Analytical methods
- Zebra/Quagga Mussel APHA 10200G Modified
- Phosphorus by Single Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Turbidity by Nephelometry
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
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory