Skip to main content
LakeQuality
Late afternoon sun over Slim Lake, scattering a bright path across wind-textured water
NR

Hill County Lake Quality

Montana, 25 lakes — no lake here has enough monitoring data for a grade

There are 25 monitored lakes in Hill County. The mix is varied enough that the county-level average tells you the broad strokes, not the choose-this-cabin specifics. No lake in Hill County has enough sampling behind it for an A–F grade yet. The 25 monitored lakes below carry whatever clarity, phosphorus, and chlorophyll-a measurements exist.

Most of the county's monitored lakes are shallow, under 50 feet, which means wind keeps the water column mixed all summer and sediment-bound phosphorus releases back into the surface layer whenever the bottom is disturbed.

Loading map…

Where to stay near Hill County

Top-rated places to stay near Hill County

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 to Hill County?

Get lake water-quality report cards plus the best cabin & lodging deals near Hill County — straight to your inbox. No spam, unsubscribe anytime.

All Lakes in Hill County

25 lakes · 0 graded, 25 not rated0 graded lakes · 25 not rated, hidden

#LakeGradeClarityPhosphorusAlgaeTrophicAccess
NRMcKinnsey ReservoirHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRBurkhartsmeyer ReservoirHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRHingham LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRLower LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRBearpaw LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRBailey ReservoirHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRSage LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRDry LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRChain of LakesHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRChain of LakesHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRFresno ReservoirHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRSands LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRHalfway LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMartin LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRDry LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRGrassy LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRLake ThibadeauHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRDiversionHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMud LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMud LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMud LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMud LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRMud LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRGrassy LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded
NRGrassy LakeHillNRNo recent samplesNo recent samplesNo recent samplesNo recent samplesNot recorded

NR = not rated: there is not enough recent sampling to support a letter. That is EPA Integrated Reporting Category 3 (insufficient information), not a failing grade. How grading works.

Lake Match

Which lake suits how you actually use one?

Six questions — swimming, fishing, quiet, cabins, drive time — and a shortlist of graded lakes that fit, with the water quality behind each one.

Take the quiz →

See how Hill County stacks up in the national county water-quality rankings, or browse the full directory of graded lakes across all United States (49 states), Canada (Ontario, Québec, Nova Scotia, British Columbia and Newfoundland and Labrador), and 38 other country hubs..

Source: EPA National Aquatic Resource Surveys, 2026.