Miramonte Reservoir
San Miguel County, Colorado410 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.
- 13 ft max depth
- Public access
- Limited data
Miramonte Reservoir in San Miguel County, Colorado is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.8 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Surface area: 410 acres.
- Clarity
- 2.8 ft
- Max depth
- ~13 ft est.
- Area
- 410 acres
- Public access
- Yes
Stays via Stay22
Stays near Miramonte Reservoir
Compare lakeside cabins, hotels, and vacation rentals near Miramonte Reservoir in San Miguel County, Colorado — 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 Miramonte Reservoir
Prices for Sep 4–6, 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 Miramonte Reservoir → · more Colorado lake trips
Watch Miramonte Reservoir’s letter
Email me if this lake’s grade moves. Grades stay free.
Or email
Why Miramonte Reservoir 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 Miramonte Reservoir, 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 CDPHE and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Miramonte Reservoir is a 410-acre lake in San Miguel County, Colorado with an estimated average depth of about 13 feet. Limited fish-species data available. Public access is available with 2 public boat landings.
Source: EPA Water Quality Portal sampling records, CDPHE, last sampled 2023-09-19. Grade methodology: LakeQuality methodology.
What Miramonte Reservoir is good for
From access and monitoring records, not editorial picks.
- Boat launch2 documented ramps
Swimming Safety
Not ratedLimited data
The letter is not a swimming clearance. Miramonte Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO). Check local advisories before you swim.
Water quality measurements for Miramonte Reservoir
These readings exist but are not enough for an A–F grade — see why.
Very murky, less than 2.8 ft of visibility. Phosphorus 25 µg/L. Chlorophyll-a 7.3 µg/L. TSI 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.8 ft | Not graded |
| Phosphorus | 25 µg/L | Not graded |
| Chlorophyll-a (Algae) | 7.3 µg/L | Not graded |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~13 ft est. |
| Average Depth | ~11 ft est. |
| Surface Area | 410 acres |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Colorado has not published bathymetry for Miramonte Reservoir.
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.
Recreation & Access
- Dan Noble State Wildlife AreaPublic
- Dan Noble State Wildlife AreaPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Miramonte Reservoir
Reservoir Info (USACE NID)
Miramonte Reservoir is a man-made reservoir impounded by the Miramonte (completed 1978), built primarily for recreation on the West Naturita Creek; earth-type dam, 87 ft tall and 620 ft long.
- Surface area
- 410 ac
- Normal storage
- 6,851 ac-ft
- Max storage
- 11,620 ac-ft
- Drainage area
- 36 sq mi
- Hazard class
- High
- Owner
- COLORADO PARKS AND WILDLIFE
All listed purposes: Recreation;Fish and Wildlife Pond.
Source: USACE National Inventory of Dams, NID ID CO00162 · Operator website
EPA Impairment Status
Miramonte Reservoir is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit COGUSM20_B · Official waterbody report
Graded lakes near Miramonte Reservoir
Miramonte Reservoir has no grade, but these lakes within a short drive do.
Nearby Lakes in San Miguel County
Frequently asked questions about Miramonte Reservoir
Where is Miramonte Reservoir?
- Miramonte Reservoir is a lake in San Miguel County, Colorado. 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 Miramonte Reservoir?
- Miramonte Reservoir in San Miguel County, Colorado is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 2.8 ft visibility. Phosphorus: 25 µg/L. Chlorophyll-a (algae): 7.3 µg/L. Surface area: 410 acres.
Is Miramonte Reservoir safe to swim in?
- The letter is not a swimming clearance. Miramonte Reservoir is listed impaired under Clean Water Act §303(d) (IR 5) for oxygen depletion (low DO). Check local advisories before you swim.
How deep is Miramonte Reservoir?
- No published bathymetric survey covers Miramonte Reservoir, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 13 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 410 acres.
Are there boat ramps on Miramonte Reservoir?
- Miramonte Reservoir has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Dan Noble State Wildlife Area, Dan Noble State Wildlife Area. Public access is listed as yes.
Explore Miramonte Reservoir across LakeQuality
4 thermal springs within 19.6 mi, nearest Lemon Hot Spring
Species activity outlook by water temperature and season
Where to stay at Colorado's top lakes, each with its grade
Colorado's cleanest and most-polluted lakes, ranked
More Colorado Lake Rankings
Other Lakes in Colorado
Eutrophic Lakes in Colorado
Where this data comes from
6 measurements from 2 monitoring stations, 2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Colorado Dept. of Public Health & Environment-WQCD
21COL001_WQX6 samples · 2023
Analytical methods
- Secchi disk depth measurement
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Nitrogen in Water by Pyrolysis Detection
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory