Rushmore Cave is a cave in Pennington County, South Dakota. It sits roughly 14.9 km (9.3 mi) S of Colonial Pine Hills.
Rushmore Cave is the closest show cave to Mount Rushmore National Memorial in the United States. It contains a wide variety of natural formations. It is the ninth longest cave in South Dakota. It measures a distance of 3,652.6 feet (1,113.3 m).From the Wikipedia article “Rushmore Cave”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Rushmore Cave the sunrise point swings a long way through the year: about 56° (NE) at the June solstice and 123° (ESE) in late December. Sunset moves from 305° (NW) in June to 238° (WSW) in December, and the midday sun climbs to 70° in summer but only 23° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 6:57 AM | 90° E | 7:06 PM | 271° W | 46° | 12h 08m |
| June solstice (Jun 21) | 5:12 AM | 56° NE | 8:40 PM | 305° NW | 70° | 15h 28m |
| September equinox (Sep 22) | 6:41 AM | 89° E | 6:53 PM | 271° W | 46° | 12h 11m |
| December solstice (Dec 21) | 7:25 AM | 123° ESE | 4:19 PM | 238° WSW | 23° | 8h 54m |
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
Caves are lit artificially — show caves have fixed lighting, so a fast lens and high ISO beat flash, which flattens formations.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 6:53 AM | 7:25 AM | 8:10 AM | 3:56 PM | 4:42 PM | 5:14 PM | 9h 16m |
| February | 6:24 AM | 6:53 AM | 7:34 AM | 4:43 PM | 5:23 PM | 5:53 PM | 10h 30m |
| March | 6:38 AM | 7:06 AM | 7:45 AM | 6:22 PM | 7:00 PM | 7:28 PM | 11h 53m |
| April | 5:41 AM | 6:11 AM | 6:50 AM | 6:58 PM | 7:37 PM | 8:07 PM | 13h 26m |
| May | 4:55 AM | 5:29 AM | 6:10 AM | 7:31 PM | 8:13 PM | 8:46 PM | 14h 44m |
| June | 4:35 AM | 5:11 AM | 5:55 AM | 7:54 PM | 8:38 PM | 9:14 PM | 15h 27m |
| July | 4:51 AM | 5:25 AM | 6:08 AM | 7:51 PM | 8:34 PM | 9:09 PM | 15h 09m |
| August | 5:27 AM | 5:58 AM | 6:38 AM | 7:19 PM | 7:59 PM | 8:30 PM | 14h 01m |
| September | 6:04 AM | 6:33 AM | 7:11 AM | 6:28 PM | 7:06 PM | 7:34 PM | 12h 32m |
| October | 6:39 AM | 7:08 AM | 7:47 AM | 5:32 PM | 6:11 PM | 6:40 PM | 11h 03m |
| November | 6:18 AM | 6:49 AM | 7:32 AM | 3:45 PM | 4:29 PM | 5:00 PM | 9h 40m |
| December | 6:49 AM | 7:22 AM | 8:09 AM | 3:30 PM | 4:17 PM | 4:50 PM | 8h 56m |
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 Rushmore Cave, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 3.7 hours on a moonless night), and the core peaks around 17° above the southern horizon. Our light-pollution model puts the sky at about Bortle 3 (rural sky), good enough for detailed Milky Way images.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -4° | — |
| February | Below 10° in darkness | — | 8° | — |
| March | 4:45 AM – 5:25 AM | 0.7 | 14° | SSE → SSE |
| April | 2:41 AM – 4:21 AM | 1.7 | 17° | SSE → S |
| May | 12:45 AM – 3:15 AM | 2.5 | 17° | SSE → S |
| June | 11:00 PM – 2:40 AM | 3.7 | 17° | SSE → SSW |
| July | 10:47 PM – 1:27 AM | 2.7 | 17° | S → SSW |
| August | 9:50 PM – 11:20 PM | 1.5 | 16° | S → SSW |
| September | 8:43 PM – 9:23 PM | 0.7 | 14° | SSW → SSW |
| October | Below 10° in darkness | — | 8° | — |
| November | Below 10° in darkness | — | -2° | — |
| 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: 3 Bortle 3 — Rural sky. Some light domes sit on the horizon, but the Milky Way still looks complex overhead. Modeled zenith brightness ≈ 21.65 mag/arcsec². Aurora needs roughly Kp 5.5+ to show low on the northern horizon here.
Weather & best season
Long-term NASA satellite data for this area show September as the clearest month (about 43% average cloud cover) and February as the cloudiest (64%). 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 | 63 | 69 | 79 | 87 | 95 | 106 | 108 | 104 | 101 | 89 | 76 | 64 |
| Low °F | -10 | -12 | -9 | 8 | 20 | 36 | 46 | 40 | 28 | 2 | -2 | -13 |
| Precip. (in) | 0.4 | 0.6 | 1.0 | 2.0 | 3.1 | 2.6 | 2.2 | 1.7 | 1.4 | 1.2 | 0.5 | 0.4 |
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 cave
- Follow White-nose Syndrome decontamination rules where posted to protect bats.
- Many show caves restrict tripods on tours; ask in advance or bring a small beanbag.
- Use manual focus with focus peaking in low light.
- Never touch formations — skin oils stop their growth.
- Check road and trail conditions with the managing agency before you go.
Season: Cave interiors stay at a constant temperature year-round; summer tours fill up, so book ahead.
Suggested gear: Fast lens (f/1.8–f/2.8), High-ISO camera, Small beanbag. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Rushmore Cave, closest first.
Scenic ViewpointScenic ViewpointScenic Viewpoint
Cave
Mountain Peak
WaterfallScenic Viewpoint
State Park
Fire LookoutCampgrounds nearby (Recreation.gov)
- Grizzly Bear Campground8.4 km (5.2 mi) · reservable
- Horsethief Lake Campground12.4 km (7.7 mi) · reservable
- Iron Creek Horse Camp13.0 km (8.1 mi) · reservable
- Sheridan Lake16.3 km (10.1 mi) · reservable
- Sheridan North Cove Grp Cg16.6 km (10.3 mi) · reservable
FAQ
When is the best time to photograph Rushmore Cave?
What time is golden hour at Rushmore Cave?
Where does the sun rise and set at Rushmore Cave?
Can you see the Milky Way from Rushmore Cave?
Do you need a permit to photograph at Rushmore Cave?
How far is Rushmore Cave from Colonial Pine Hills?
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.