Mercer Caverns — a cave in Calaveras County, California — is a classic subject for landscape photographers. The nearest town is Murphys, about 2.1 km (1.3 mi) away (Mercer Caverns lies NW of town).
Mercer Caverns is a show cave located one mile north of Murphys in Calaveras County California. It is named after the gold prospector Walter J. Mercer who discovered the caves around 1885 and filed a claim. The caverns have a large number of speleothems, stalactites, and stalagmites. It is formed in a marble unit known as the Calaveras Formation. It also contains a large display of aragonite frostwork. The standard tour of the cave descends 160 feet, 208 steps down and 232 up in a traverse between the natural and an artificial entrance. The cave was mapped in 1986 to a length of 3389 feet and a total depth of 192 feet. The map can be viewed on the cave's web site.From the Wikipedia article “Mercer Caverns”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Mercer Caverns the sunrise point swings a long way through the year: about 59° (ENE) at the June solstice and 120° (ESE) in late December. Sunset moves from 301° (WNW) in June to 241° (WSW) in December, and the midday sun climbs to 75° in summer but only 28° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:06 AM | 90° E | 7:14 PM | 271° W | 52° | 12h 08m |
| June solstice (Jun 21) | 5:40 AM | 59° ENE | 8:29 PM | 301° WNW | 75° | 14h 49m |
| September equinox (Sep 22) | 6:50 AM | 89° E | 7:00 PM | 271° W | 52° | 12h 10m |
| December solstice (Dec 21) | 7:16 AM | 120° ESE | 4:46 PM | 241° WSW | 28° | 9h 31m |
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 | 6:49 AM | 7:18 AM | 7:58 AM | 4:26 PM | 5:06 PM | 5:35 PM | 9h 48m |
| February | 6:26 AM | 6:53 AM | 7:30 AM | 5:04 PM | 5:41 PM | 6:08 PM | 10h 48m |
| March | 6:48 AM | 7:14 AM | 7:49 AM | 6:35 PM | 7:09 PM | 7:36 PM | 11h 56m |
| April | 6:00 AM | 6:27 AM | 7:02 AM | 7:03 PM | 7:38 PM | 8:05 PM | 13h 11m |
| May | 5:22 AM | 5:52 AM | 6:30 AM | 7:29 PM | 8:06 PM | 8:36 PM | 14h 14m |
| June | 5:08 AM | 5:39 AM | 6:19 AM | 7:48 PM | 8:27 PM | 8:59 PM | 14h 48m |
| July | 5:21 AM | 5:52 AM | 6:30 AM | 7:47 PM | 8:25 PM | 8:56 PM | 14h 34m |
| August | 5:50 AM | 6:18 AM | 6:54 AM | 7:21 PM | 7:57 PM | 8:25 PM | 13h 39m |
| September | 6:18 AM | 6:44 AM | 7:19 AM | 6:37 PM | 7:12 PM | 7:38 PM | 12h 27m |
| October | 6:45 AM | 7:11 AM | 7:47 AM | 5:50 PM | 6:25 PM | 6:52 PM | 11h 14m |
| November | 6:16 AM | 6:44 AM | 7:23 AM | 4:12 PM | 4:51 PM | 5:19 PM | 10h 07m |
| December | 6:43 AM | 7:12 AM | 7:53 AM | 4:03 PM | 4:44 PM | 5:13 PM | 9h 32m |
Local time (America/Los Angeles), 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 Mercer Caverns, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 5.2 hours on a moonless night), and the core peaks around 23° above the southern horizon. Our light-pollution model puts the sky at about Bortle 4 (rural / suburban transition), good enough for detailed Milky Way images.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -1° | — |
| February | 5:00 AM – 5:20 AM | 0.3 | 13° | SE → SE |
| March | 4:07 AM – 5:37 AM | 1.5 | 19° | SE → SSE |
| April | 2:12 AM – 4:42 AM | 2.5 | 22° | SE → S |
| May | 12:12 AM – 4:02 AM | 3.8 | 23° | SE → SSW |
| June | 10:24 PM – 3:34 AM | 5.2 | 23° | SE → SSW |
| July | 10:17 PM – 2:17 AM | 4.0 | 23° | SSE → SW |
| August | 9:35 PM – 12:15 AM | 2.7 | 23° | S → SW |
| September | 8:41 PM – 10:11 PM | 1.5 | 19° | SSW → SW |
| October | 7:53 PM – 8:13 PM | 0.3 | 13° | SW → SW |
| November | Below 10° in darkness | — | 0° | — |
| December | Below 10° in darkness | — | -19° | — |
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: 4 Bortle 4 — Rural / suburban transition. Light domes are visible in several directions; the Milky Way is clear but lacks detail near the horizon. Modeled zenith brightness ≈ 21.17 mag/arcsec².
Weather & best season
Long-term NASA satellite data for this area show August as the clearest month (about 14% average cloud cover) and December as the cloudiest (62%). 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 | 72 | 70 | 75 | 84 | 97 | 104 | 107 | 103 | 107 | 97 | 83 | 70 |
| Low °F | 17 | 9 | 17 | 26 | 32 | 38 | 46 | 46 | 38 | 32 | 12 | 13 |
| Precip. (in) | 4.7 | 5.4 | 4.9 | 3.0 | 1.6 | 0.4 | 0.1 | 0.1 | 0.2 | 1.7 | 3.4 | 6.0 |
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 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.
- Tell someone where you're going in remote areas and carry the ten essentials.
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 Mercer Caverns, closest first.
Cave
Cave
Natural Arch
State Park
Scenic Viewpoint
State Park
State Park
National ForestCampgrounds nearby (Recreation.gov)
- Glory Hole Recreation Area16.9 km (10.5 mi) · reservable
- Tuttletown Recreation Area18.8 km (11.7 mi) · reservable
- Acorn Campground28 km (18 mi) · reservable
- Sand Bar Flat Campground28 km (18 mi)
- Oak Knoll Campground29 km (18 mi) · reservable
FAQ
When is the best time to photograph Mercer Caverns?
What time is golden hour at Mercer Caverns?
Where does the sun rise and set at Mercer Caverns?
Can you see the Milky Way from Mercer Caverns?
Do you need a permit to photograph at Mercer Caverns?
How far is Mercer Caverns from Murphys?
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.