Standley Lake is a cold, clear oligotrophic lake in Jefferson County, Colorado. Water quality is graded A based on 1 sampling years through 2025. Compared to the 1 other monitored lakes in Jefferson County, Standley Lake ranks #1 for water quality.
Source: EPA Water Quality Portal sampling records, Colorado DNR, last sampled 2025-07-28. Grade methodology: LakeGrade methodology.
Watch Standley Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
Crystal clear, you can see 20.5 ft down. Trophic State Index: 34.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 20.5 ft | A |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 34 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Standley Lake
Compare lakeside cabins, hotels, and vacation rentals near Standley Lake in Jefferson County, Colorado — live availability and prices for your trip.
Top-rated places to stay near Standley Lake
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 to Standley Lake?
Get lake water-quality report cards plus the best cabin & lodging deals near Standley Lake — straight to your inbox. No spam, unsubscribe anytime.
Fishing Standley Lake
Location
County Ranking
Ranked #1 of 2 lakes in Jefferson County
Nearby Lakes in Jefferson County
Explore Standley Lake across LakeGrade
More Colorado Lake Rankings
Other Grade A Lakes in Colorado
Oligotrophic Lakes in Colorado
More records, surveys & data sources
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2025-07-28
Monitoring stations: 1