Tongue River Cave is a cave in Sheridan County, Wyoming. It sits roughly 30 km (19 mi) W of Sheridan.
Tongue River Cave is a cave in the Bighorn National Forest just west of Dayton, Wyoming, United States. Historically notable for a wide variety of rare cave formations and animal species, the cave has suffered in recent decades from unrestricted traffic, vandalism, and the theft of many of the cave's speleothems. Deemed beyond preservation, the cave is now managed by the U.S. Forest Service as a "sacrifice cave". The Bighorn National Forest closed the cave to the public in July 2010 to prevent the spread of white-nose syndrome; however, the cave has since been reopened. Registration and decontamination of clothing and gear is now required to visit the cave per Forest Order.From the Wikipedia article “Tongue River Cave”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Tongue River Cave 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 69° in summer but only 22° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:13 AM | 90° E | 7:22 PM | 271° W | 45° | 12h 09m |
| June solstice (Jun 21) | 5:24 AM | 55° NE | 9:00 PM | 305° NW | 69° | 15h 36m |
| September equinox (Sep 22) | 6:57 AM | 89° E | 7:09 PM | 271° W | 45° | 12h 11m |
| December solstice (Dec 21) | 7:45 AM | 123° ESE | 4:32 PM | 237° WSW | 22° | 8h 47m |
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 | 7:11 AM | 7:44 AM | 8:31 AM | 4:08 PM | 4:55 PM | 5:27 PM | 9h 10m |
| February | 6:41 AM | 7:11 AM | 7:52 AM | 4:57 PM | 5:38 PM | 6:08 PM | 10h 27m |
| March | 6:54 AM | 7:23 AM | 8:01 AM | 6:37 PM | 7:16 PM | 7:45 PM | 11h 53m |
| April | 5:55 AM | 6:25 AM | 7:05 AM | 7:15 PM | 7:54 PM | 8:25 PM | 13h 29m |
| May | 5:08 AM | 5:42 AM | 6:24 AM | 7:49 PM | 8:31 PM | 9:06 PM | 14h 50m |
| June | 4:46 AM | 5:23 AM | 6:08 AM | 8:13 PM | 8:58 PM | 9:35 PM | 15h 34m |
| July | 5:02 AM | 5:38 AM | 6:22 AM | 8:10 PM | 8:54 PM | 9:29 PM | 15h 16m |
| August | 5:40 AM | 6:12 AM | 6:53 AM | 7:37 PM | 8:17 PM | 8:49 PM | 14h 05m |
| September | 6:19 AM | 6:49 AM | 7:27 AM | 6:43 PM | 7:22 PM | 7:51 PM | 12h 33m |
| October | 6:56 AM | 7:25 AM | 8:05 AM | 5:46 PM | 6:26 PM | 6:56 PM | 11h 01m |
| November | 6:36 AM | 7:07 AM | 7:52 AM | 3:58 PM | 4:42 PM | 5:14 PM | 9h 35m |
| December | 7:07 AM | 7:41 AM | 8:29 AM | 3:41 PM | 4:30 PM | 5:03 PM | 8h 49m |
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 Tongue River Cave, the Milky Way core is visible in a dark sky from April through September. June gives the longest window (about 3.3 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 | 5:13 AM – 5:33 AM | 0.3 | 12° | SSE → SSE |
| April | 3:11 AM – 4:31 AM | 1.3 | 16° | SSE → S |
| May | 1:09 AM – 3:29 AM | 2.3 | 16° | SSE → S |
| June | 11:28 PM – 2:48 AM | 3.3 | 16° | SSE → SSW |
| July | 11:12 PM – 1:32 AM | 2.3 | 16° | S → SSW |
| August | 10:11 PM – 11:31 PM | 1.3 | 15° | SSW → SSW |
| September | 9:02 PM – 9:32 PM | 0.5 | 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 ≈ 21.9 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 May as the cloudiest (66%). 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 | 39 | 42 | 58 | 69 | 75 | 86 | 92 | 90 | 82 | 73 | 57 | 42 |
| Low °F | -34 | -32 | -21 | -10 | 6 | 21 | 33 | 27 | 11 | -15 | -21 | -32 |
| Precip. (in) | 1.3 | 1.6 | 1.8 | 2.5 | 3.5 | 2.5 | 1.4 | 1.4 | 2.0 | 2.2 | 1.4 | 1.2 |
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
- Never touch formations — skin oils stop their growth.
- 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.
- Shoot RAW to keep the most latitude for high-contrast sunrise and sunset scenes.
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 Tongue River Cave, closest first.
Campgrounds nearby (Recreation.gov)
- Sibley Lake12.0 km (7.4 mi) · reservable
- Burgess Junction Visitor Center13.5 km (8.4 mi) · reservable
- Prune Creek13.7 km (8.5 mi) · reservable
- Pine Island Group Area13.7 km (8.5 mi) · reservable
- North Tongue17.4 km (10.8 mi) · reservable
FAQ
When is the best time to photograph Tongue River Cave?
What time is golden hour at Tongue River Cave?
Where does the sun rise and set at Tongue River Cave?
Can you see the Milky Way from Tongue River Cave?
Do you need a permit to photograph at Tongue River Cave?
How far is Tongue River Cave from Sheridan?
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.