Castle Rock Butte is a rock formation in Butte County, South Dakota. It sits roughly 49 km (30 mi) NE of Belle Fourche.
Castle Rock Butte is a summit in Butte County, South Dakota, in the United States. With an elevation of 3,768 feet (1,148 m), Castle Rock Butte is the 235th highest summit in the state of South Dakota. The Castle Rock Butte was used by Native Americans, explorers and early settlers as a lookout and reference point during their travels. The butte looked to many travelers like a castle on a hill. The name is credited to Dr. Edwin James, a botanist on Long's Expedition of 1820. The town of Castle Rock is named after this solitary natural landmark. Castle Rock was so named on account of its castle-like outline.From the Wikipedia article “Castle Rock Butte”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Castle Rock Butte the sunrise point swings a long way through the year: about 55° (NE) at the June solstice and 123° (ESE) in late December. Sunset moves from 305° (NW) in June to 237° (WSW) in December, and the midday sun climbs to 68° in summer but only 22° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 6:58 AM | 90° E | 7:06 PM | 271° W | 45° | 12h 09m |
| June solstice (Jun 21) | 5:08 AM | 55° NE | 8:45 PM | 305° NW | 68° | 15h 37m |
| September equinox (Sep 22) | 6:42 AM | 89° E | 6:53 PM | 271° W | 45° | 12h 12m |
| December solstice (Dec 21) | 7:30 AM | 123° ESE | 4:16 PM | 237° WSW | 22° | 8h 46m |
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
Rock towers and buttes glow red and orange in the first and last half-hour of sun; midday light flattens their shape.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:56 AM | 7:29 AM | 8:16 AM | 3:52 PM | 4:38 PM | 5:11 PM | 9h 09m |
| February | 6:26 AM | 6:56 AM | 7:37 AM | 4:41 PM | 5:22 PM | 5:52 PM | 10h 26m |
| March | 6:38 AM | 7:07 AM | 7:46 AM | 6:21 PM | 7:00 PM | 7:29 PM | 11h 53m |
| April | 5:39 AM | 6:10 AM | 6:49 AM | 7:00 PM | 7:39 PM | 8:10 PM | 13h 29m |
| May | 4:51 AM | 5:26 AM | 6:08 AM | 7:34 PM | 8:16 PM | 8:51 PM | 14h 51m |
| June | 4:30 AM | 5:07 AM | 5:52 AM | 7:58 PM | 8:43 PM | 9:20 PM | 15h 36m |
| July | 4:46 AM | 5:22 AM | 6:06 AM | 7:55 PM | 8:39 PM | 9:15 PM | 15h 17m |
| August | 5:24 AM | 5:56 AM | 6:37 AM | 7:22 PM | 8:02 PM | 8:34 PM | 14h 06m |
| September | 6:04 AM | 6:33 AM | 7:12 AM | 6:28 PM | 7:07 PM | 7:36 PM | 12h 33m |
| October | 6:40 AM | 7:10 AM | 7:50 AM | 5:30 PM | 6:10 PM | 6:40 PM | 11h 00m |
| November | 6:21 AM | 6:52 AM | 7:37 AM | 3:42 PM | 4:26 PM | 4:58 PM | 9h 34m |
| December | 6:52 AM | 7:26 AM | 8:15 AM | 3:25 PM | 4:14 PM | 4:47 PM | 8h 47m |
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 Castle Rock Butte, the Milky Way core is visible in a dark sky from April through August. June gives the longest window (about 3.2 hours on a moonless night), and the core peaks around 16° above the southern horizon. Our light-pollution model puts the sky at about Bortle 1 (excellent dark-sky site), which is excellent for astrophotography.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -4° | — |
| February | Below 10° in darkness | — | 7° | — |
| March | 4:58 AM – 5:18 AM | 0.3 | 12° | SSE → SSE |
| April | 2:57 AM – 4:17 AM | 1.3 | 15° | SSE → S |
| May | 12:55 AM – 3:05 AM | 2.2 | 16° | SSE → S |
| June | 11:16 PM – 2:26 AM | 3.2 | 16° | SSE → SSW |
| July | 10:59 PM – 1:09 AM | 2.2 | 16° | S → SSW |
| August | 9:57 PM – 11:07 PM | 1.2 | 15° | SSW → SSW |
| September | 8:47 PM – 9:07 PM | 0.3 | 12° | SSW → SSW |
| October | Below 10° in darkness | — | 7° | — |
| November | Below 10° in darkness | — | -3° | — |
| 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: 1 Bortle 1 — Excellent dark-sky site. The Milky Way casts faint shadows; zodiacal light and airglow are obvious. Modeled zenith brightness ≈ 21.93 mag/arcsec². Aurora needs roughly Kp 5.0+ 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 40% average cloud cover) and March as the cloudiest (65%). July is the warmest month and January 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 | 63 | 70 | 81 | 88 | 96 | 109 | 108 | 107 | 101 | 91 | 74 | 65 |
| Low °F | -15 | -15 | -18 | 10 | 22 | 34 | 47 | 42 | 29 | 4 | -2 | -17 |
| Precip. (in) | 0.4 | 0.6 | 0.8 | 1.7 | 2.9 | 2.8 | 2.0 | 1.8 | 1.4 | 1.3 | 0.4 | 0.5 |
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 rock formation
- Find a spot where the formation sits against open sky to emphasize its silhouette.
- At night, a formation under the Milky Way or star trails makes a strong anchor.
- Use the sunrise and sunset azimuths below to know which face will be lit.
- Stay on trails; desert soils and lichens take decades to recover from footprints.
- Check road and trail conditions with the managing agency before you go.
Season: Spring and autumn are best in desert regions; winter snow on red rock is rare but spectacular.
Suggested gear: Wide and telephoto lenses, Tripod, Headlamp. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Castle Rock Butte, closest first.
FAQ
When is the best time to photograph Castle Rock Butte?
What time is golden hour at Castle Rock Butte?
Where does the sun rise and set at Castle Rock Butte?
Can you see the Milky Way from Castle Rock Butte?
Do you need a permit to photograph at Castle Rock Butte?
How far is Castle Rock Butte from Belle Fourche?
Sources
Location data: Wikidata, 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.