Prineville Reservoir
Crook County, Oregon3,028 acresView mapDirections
Nutrients and algae run above the regional average.
↓ down from B at the last regrade
- Eutrophic
- Impaired · Hydrologic alteration
- #2 of 3 in the county
- Public access
- Limited data
Prineville Reservoir in Crook County, Oregon has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 7.5 µg/L. Surface area: 3028 acres.
- Area
- 3,028 acres
- Type
- Eutrophic
- Chlorophyll-a
- 7.5 µg/L
- Trend
- ↓ Declining
- Public access
- Yes
Stays via Stay22
Stays near Prineville Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Prineville Reservoir in Crook 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Prineville Reservoir are listed below.
Top-rated places to stay near Prineville Reservoir
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 Prineville Reservoir → · more Oregon lake trips
Watch Prineville Reservoir’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Prineville Reservoir is a 3,028-acre productive, nutrient-rich eutrophic lake in Crook County, Oregon. Water quality is graded D based on 1 sampling years through 2025. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available with 5 public boat landings. Compared to the 2 other monitored lakes in Crook County, Prineville Reservoir ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Oregon DEQ, last sampled 2025-09-23. Grade methodology: LakeQuality methodology.
What Prineville Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch5 documented ramps
- Camping2 public campgrounds nearby
- Big water3,028 acres
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 D is nutrients and algae, not a swimming clearance. Prineville Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for hydrologic alteration, mercury, metals (other than mercury), temperature. Check local advisories before you swim.
Water Quality Grade: D (Nutrient-rich)
No clarity data. Chlorophyll-a 7.5 µg/L. TSI 50. The letter is not a swimming clearance.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No recent samples | |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | 7.5 µg/L | Poor |
| Trophic State Index (TSI) | 50 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Surface Area | 3,028 acres |
| Public Access | Yes |
No bathymetric survey has been published for Prineville Reservoir, so its depth is not documented here.
Recreation & Access
- Prineville Reservoir State ParkPublic
- County RampPublic
- Jasper PointPublic
- Roberts Bay EastPublic
- Prineville Reservoir ResortSemi-private
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Public campgrounds near Prineville Reservoir
- Prineville Reservoir State Park Campground0.4 km
- Prineville Reservoir State Park Jasper Point Campground2.5 km
Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes
Fishing Prineville Reservoir
Water Quality Trend: ↓ Declining
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Chlorophyll-a | ↓ Declining | +2.6 µg/L/yr | 2 |
Reservoir Info (USACE NID)
Prineville Reservoir is a man-made reservoir impounded by the Arthur R. Bowman Dam (completed 1961), built primarily for flood risk reduction on the Crooked River; earth-type dam, 245 ft tall and 790 ft long.
- Surface area
- 3,028 ac
- Normal storage
- 150,216 ac-ft
- Max storage
- 281,920 ac-ft
- Drainage area
- 2,522.33 sq mi
- Hazard class
- High
- Owner
- BUREAU OF RECLAMATION
All listed purposes: Flood Risk Reduction;Irrigation.
Source: USACE National Inventory of Dams, NID ID OR00579 · Operator website
EPA Impairment Status
Prineville Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2022 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit OR_LK_1707030408_02_100106 · Official waterbody report
County Ranking
Ranked #2 of 3 lakes in Crook County
Nearby Lakes in Crook County
Frequently asked questions about Prineville Reservoir
Where is Prineville Reservoir?
- Prineville Reservoir is a lake in Crook County, Oregon. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Prineville Reservoir?
- Prineville Reservoir in Crook County, Oregon has a water quality grade of D (Nutrient-rich). Chlorophyll-a (algae): 7.5 µg/L. Surface area: 3028 acres.
Is Prineville Reservoir safe to swim in?
- The D is nutrients and algae, not a swimming clearance. Prineville Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for hydrologic alteration, mercury, metals (other than mercury), temperature. Check local advisories before you swim.
Are there boat ramps on Prineville Reservoir?
- Prineville Reservoir has 5 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Prineville Reservoir State Park, County Ramp, Jasper Point, Roberts Bay East, among others. Public access is listed as yes.
Are there campgrounds on Prineville Reservoir?
- Prineville Reservoir has 2 public campgrounds from USGS The National Map within 5 km, including Prineville Reservoir State Park Campground, Prineville Reservoir State Park Jasper Point Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.
Explore Prineville Reservoir across LakeQuality
Depth, room, public access, and the state wake-sport rules
Species activity outlook by water temperature and season
Where to stay at Oregon's top lakes, each with its grade
High nutrients, frequent algae, reduced clarity
Oregon's cleanest and most-polluted lakes, ranked
More Oregon Lake Rankings
Other Grade D Lakes in Oregon
Jefferson County · Nutrient-rich
Jefferson County · Nutrient-rich
Jefferson County · Nutrient-rich
Jefferson County · 4.6 ft
Jefferson County · 5.6 ft
Deschutes County · 17.6 ft
Eutrophic Lakes in Oregon
Where this data comes from
8 measurements from 1 monitoring station, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Department of Environmental Quality - State of Oregon
OREGONDEQ8 samples · 2024–2025
Analytical methods
- 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
Impairment status from EPA ATTAINS 303(d) database
Named boat-access points from the USGS National Boat Ramps inventory
Public campgrounds from USGS The National Map Structures, within about 3 miles