Located in Cascade County, Montana, Colter Falls is a waterfall at about 986 m (3,235 ft) above sea level. It sits roughly 4.3 km (2.7 mi) NW of Malmstrom Air Force Base.
Colter Falls, also called Coulter Falls, is a submerged waterfall on the Missouri River in north-central Montana, and part of the Great Falls of the Missouri. Downstream of Colter Falls lies Rainbow Falls, and upstream is Black Eagle Falls. The falls is now flooded in the impoundment behind Rainbow Dam. As Rainbow Dam's reservoir is a run-of-the-river reservoir, it rarely is emptied, so the falls are rarely seen even in extreme drought.From the Wikipedia article “Colter Falls”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Colter Falls the sunrise point swings a long way through the year: about 53° (NE) at the June solstice and 125° (SE) in late December. Sunset moves from 307° (NW) in June to 235° (SW) in December, and the midday sun climbs to 66° in summer but only 19° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:29 AM | 89° E | 7:38 PM | 271° W | 42° | 12h 09m |
| June solstice (Jun 21) | 5:28 AM | 53° NE | 9:27 PM | 307° NW | 66° | 15h 59m |
| September equinox (Sep 22) | 7:12 AM | 89° E | 7:24 PM | 271° W | 43° | 12h 12m |
| December solstice (Dec 21) | 8:11 AM | 125° SE | 4:37 PM | 235° SW | 19° | 8h 26m |
Azimuth is measured clockwise from true north (90° = east, 270° = west). Computed for 2026; values change by less than a degree from year to year.
Golden hour & blue hour by month
Waterfalls photograph best in soft, even light: overcast days, deep shade, or the hour after sunrise before direct sun hits the water. Bright sun on white water blows highlights and adds harsh contrast.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:34 AM | 8:09 AM | 8:59 AM | 4:11 PM | 5:01 PM | 5:36 PM | 8h 52m |
| February | 7:00 AM | 7:31 AM | 8:15 AM | 5:05 PM | 5:48 PM | 6:20 PM | 10h 17m |
| March | 7:08 AM | 7:39 AM | 8:20 AM | 6:50 PM | 7:31 PM | 8:01 PM | 11h 52m |
| April | 6:04 AM | 6:37 AM | 7:18 AM | 7:33 PM | 8:14 PM | 8:47 PM | 13h 37m |
| May | 5:12 AM | 5:49 AM | 6:33 AM | 8:11 PM | 8:56 PM | 9:32 PM | 15h 07m |
| June | 4:47 AM | 5:28 AM | 6:16 AM | 8:37 PM | 9:25 PM | 10:05 PM | 15h 57m |
| July | 5:05 AM | 5:44 AM | 6:30 AM | 8:33 PM | 9:19 PM | 9:58 PM | 15h 36m |
| August | 5:48 AM | 6:22 AM | 7:04 AM | 7:56 PM | 8:39 PM | 9:13 PM | 14h 17m |
| September | 6:32 AM | 7:03 AM | 7:44 AM | 6:58 PM | 7:39 PM | 8:10 PM | 12h 36m |
| October | 7:13 AM | 7:44 AM | 8:26 AM | 5:56 PM | 6:38 PM | 7:09 PM | 10h 54m |
| November | 6:57 AM | 7:31 AM | 8:18 AM | 4:03 PM | 4:50 PM | 5:24 PM | 9h 19m |
| December | 7:31 AM | 8:07 AM | 9:00 AM | 3:42 PM | 4:35 PM | 5:11 PM | 8h 28m |
Local time (America/Denver), including daylight saving time. Golden hour runs from about −4° to +6° solar altitude, so the morning golden hour begins during blue hour, before sunrise.
Milky Way & night sky
From Colter Falls, the Milky Way core is visible in a dark sky from April through August. June gives the longest window (about 1.8 hours on a moonless night), and the core peaks around 14° above the southern horizon. Our light-pollution model puts the sky at about Bortle 5 (suburban sky), so expect visible sky glow; drive away from towns for better results.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -6° | — |
| February | Below 10° in darkness | — | 5° | — |
| March | 5:54 AM – 5:54 AM | 0.0 | 10° | SSE → SSE |
| April | 3:59 AM – 4:39 AM | 0.7 | 13° | SSE → SSE |
| May | 1:58 AM – 3:18 AM | 1.3 | 13° | SSE → S |
| June | 12:29 AM – 2:19 AM | 1.8 | 14° | SSE → S |
| July | 12:00 AM – 1:20 AM | 1.3 | 13° | S → SSW |
| August | 10:43 PM – 11:13 PM | 0.5 | 12° | SSW → SSW |
| September | Below 10° in darkness | — | 9° | — |
| October | Below 10° in darkness | — | 5° | — |
| November | Below 10° in darkness | — | -4° | — |
| December | Below 10° in darkness | — | -20° | — |
Window when the galactic core is at least 10° high during astronomical darkness on the 15th of each month. Pick nights within a few days of the new moon. Plan exact nights with the Milky Way planner.
Estimated sky darkness: 5 Bortle 5 — Suburban sky. The Milky Way is weak near the horizon and washed out overhead; long exposures pick up a sky glow. Modeled zenith brightness ≈ 20.18 mag/arcsec². Aurora needs roughly Kp 4.0+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show July as the clearest month (about 38% average cloud cover) and March as the cloudiest (71%). July is the warmest month and December the coldest, which matters for gear, snow access and how long batteries last at night.
Average cloud cover (%)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 55 | 59 | 76 | 84 | 91 | 98 | 103 | 100 | 93 | 86 | 69 | 53 |
| Low °F | -30 | -26 | -25 | 7 | 18 | 34 | 42 | 40 | 18 | 5 | -12 | -19 |
| Precip. (in) | 1.0 | 1.1 | 1.1 | 2.2 | 2.6 | 3.2 | 1.2 | 1.3 | 1.7 | 1.4 | 1.0 | 1.0 |
Monthly climatology for the surrounding 1° grid cell from NASA POWER (MERRA-2). Mountain sites can be colder and cloudier than the cell average.
Photography tips for this waterfall
- A 3-stop ND filter lets you use slow shutter speeds even when the light is bright.
- Shoot a vertical and a horizontal frame; tall falls often work better in portrait orientation.
- Use 1/4 to 1 second for a silky look; 1/500 s or faster freezes individual drops.
- A circular polarizer cuts glare on wet rocks and leaves and deepens greens — rotate it while watching the rocks, not the sky.
- Bring a spare battery — cold weather and long exposures drain them fast.
Season: Peak flow is usually in late spring; autumn adds color around the falls, and winter can bring ice formations at colder locations.
Suggested gear: Tripod, Circular polarizer, 3–6 stop ND filter, Lens cloth, Waterproof footwear. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Colter Falls, closest first.
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Scenic Viewpoint
National Wildlife RefugeLake
State ParkFAQ
When is the best time to photograph Colter Falls?
What time is golden hour at Colter Falls?
Where does the sun rise and set at Colter Falls?
Can you see the Milky Way from Colter Falls?
Do you need a permit to photograph at Colter Falls?
How far is Colter Falls from Malmstrom Air Force Base?
Sources
Location data: Wikidata, USGS GNIS / GeoNames, Wikipedia. Sun, moon and Milky Way times are computed by LWPhoto Atlas for 2026. Climate: NASA POWER. Sky darkness is a population-based estimate (Walker's law), not a measurement. See data sources & licenses.