Noise Levels in Alder, MT | Find Quiet Neighborhoods With Our Sound Map
40 dBA
Average noise across Alder
Soft rainfall
3
Residents above the EPA 55 dBA threshold
2% of Alder residents
57 dBA
Loudest residential point
Normal conversation an arm’s length away
This map shows modeled outdoor noise across Alder at 100-meter resolution, combining road, aviation, and rail sources. Green areas measure below 45 dBA. Orange and red exceed the EPA's 55 dBA outdoor threshold linked to long-term health effects. Use the layer toggles to view each source on its own or all together.
Overall
Road
Rail
Aviation
Click the map to explore
35 dBa55 dBa (EPA limit)90+ dBa
3545557090
Quietest (dBA)Loudest
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What the numbers sound like
30 dBAWhisper
40 dBASoft rainfall
45 dBAQuiet suburban street at night
50 dBAQuiet office
55 dBAEPA outdoor threshold: light traffic 100 ft away
60 dBANormal conversation an arm's length away
65 dBABusy restaurant
70 dBAHighway traffic 50 ft away
80 dBACity bus interior
Population Above the EPA Outdoor Threshold
The EPA's 55 dBA outdoor reference level is a common benchmark for residential noise exposure, especially for activity interference, annoyance, and long-term community noise concerns. About 3 Alder residents, or 2.1%, live above that level. By land area, 0.1% of Alder is above 55 dBA.
Northern Alder sounds about 0% louder than Southern Alder to the human ear, a 0.0 dBA gap. Every 10 dBA roughly doubles perceived loudness. Within any of these directions, two homes a quarter mile apart can still differ by 10 or more dBA depending on how close they sit to a major highway.
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Loudest Road Corridors
The model evaluates every road in Alder using federal traffic counts, posted speeds, heavy-truck ratios, and pavement type. The source level shown is the modeled noise at the road centerline, where it is loudest. Noise drops with distance, faster in vegetated areas and slower over open pavement.
RoadTypeAvg. source dBAPeak source dBA
Hinch Creek RdLocal51.051
Garden Creek RdLocal51.051
Robb Creek RdLocal51.051
Ledford Creek RdLocal51.051
Beaver Creek RdLocal51.051
How far back from Hinch Creek Rd do you need to be?
Hinch Creek Rd produces an estimated 51 dBA at its loudest centerline points. Noise drops logarithmically with distance, with the exact rate depending on what's between you and the road. Tree cover, walls, terrain, and pavement type all matter. At roughly a quarter mile back, traffic fades into the noise level of a soft rainfall.
At source
51 dBA
Quiet office
165 ft
39 dBA
Soft rainfall
330 ft
35 dBA
Soft rainfall
660 ft
35 dBA
Soft rainfall
¼ mile
35 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 3% of Alder sits under tree canopy (much lighter than most cities) and roughly 2% is impervious surface like pavement and rooftops. Both are folded into the per-place decay rate above. Heavier canopy pulls noise down faster with distance; impervious surfaces slow the drop.
How Noise Is Distributed Across Alder
The bar chart below shows the share of Alder residents in each noise band. About 100% of residents live below the EPA's 55 dBA threshold, and roughly 0% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How Alder Compares
Alder sits at the louder end of the spectrum. Below: how Alder's average outdoor noise and share of residents above the EPA threshold compare with Ruby, Virginia City, Laurin, and Norris.
Average noise level (dBA)
Alder's 39.5 dBA pop-weighted average is at the louder end of the spectrum. Montana as a whole averages 49.0 dBA and the U.S. averages 52.0 dBA. Both are lower than Alder because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 2.1% of Alder residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's in the middle of its peer group. Measured by land area instead, 0.1% of Alder's footprint sits above 55 dBA, against a Montana average of 16.9% and a national average of 28.1%.
What This Means if You're Moving to Alder
Distance from highways matters more than the neighborhood name. Two homes in the same zip code can differ by 20 dBA if one sits 100 meters from Hinch Creek Rd and the other 500 meters away. The model captures this at 100-meter resolution, so noise exposure changes block by block.
Tree canopy can help reduce modeled noise exposure. Roughly 3% of Alder is under tree cover (much lighter than most cities), and the dominant land cover is pasture / hay. Both are measured from federal USDA Forest Service and USGS satellite imagery at 30-meter resolution. Streets with 60% or higher canopy show 3 to 5 dBA lower noise than comparable streets with bare ground or pavement, which is why the per-place decay rate above already accounts for it.
Sources & Methodology
The BestNeighborhood noise model is calibrated against nearly one million federal ground-truth measurements across four states. Road noise is computed from segment-level federal traffic data and propagated outward using physics-based acoustic decay, with attenuation rates that depend on the surrounding land cover.
All inputs are published federal datasets. Block-level noise is computed by combining road, rail, and aviation sound sources in the energy domain, the same physics used in professional environmental noise assessments. Read the full methodology.
