Merrill Cave, Lava Beds National Monument
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41.7287° N121.5489° WBortle 1Los Angeles

Merrill Cave Photography Guide

Cave in Siskiyou County, California

  • Bortle 1 sky
  • Sunset azimuth 239°–303°
  • Clearest: July
  • Milky Way Mar–Sep
Photo: Unknown author · Public domain · source

Merrill Cave — a cave in Siskiyou County, California — is a lesser-known subject for landscape photographers. It lies in or next to Lava Beds National Monument, so park hours, fees and rules apply. It sits roughly 55 km (34 mi) SSE of Altamont.

Merrill Cave is a 650 foot (200 m) former ice cave in Lava Beds National Monument in California. It was known for the pool of ice that was found year-round in the lower chamber of the cave, which fully disappeared due to compounding factors by 2005.From the Wikipedia article “Merrill Cave”, licensed under CC BY-SA 4.0.
Nearest town
Altamont
55 km (34 mi)
Sky darkness
Bortle 1
Excellent dark-sky site
Clearest month
July
18% cloud
Milky Way peak
June
4.3 h window
Golden hour (Oct)
5:48 PM
sunset 6:26 PM

Light at Merrill Cave

Live
Sunrise
7:25 AM
Sunset
6:18 PM
Golden hour AM
7:07 AM – 8:03 AM
Golden hour PM
5:40 PM – 6:36 PM
Blue hour AM
6:56 AM – 7:07 AM
Blue hour PM
6:36 PM – 6:47 PM
Full darkness
7:51 PM – 5:53 AM
Moon
Waxing Gibbous · 71%
Moonrise / set
3:40 PM / 1:24 AM
Day length
10h 54m
Sunrise azimuth
103°
Sunset azimuth
257°
000306091215182124
NightTwilightBlue hourGolden hourDaylight

Times in America/Los Angeles. Golden hour = sun −4° to +6°; blue hour = −6° to −4°.

Clouds at sunrise & sunset

NWS

Hourly sky cover from the National Weather Service. 20–60% cloud often gives the most colorful sunrises and sunsets.

Sunrise & sunset directions

At Merrill Cave the sunrise point swings a long way through the year: about 57° (ENE) at the June solstice and 122° (ESE) in late December. Sunset moves from 303° (WNW) in June to 239° (WSW) in December, and the midday sun climbs to 72° in summer but only 25° in winter.

NESW60°30°
June solsticeEquinoxesDecember solstice
DateSunriseAzimuthSunsetAzimuthNoon sunDaylight
March equinox (Mar 20)7:10 AM90° E7:19 PM271° W48°12h 08m
June solstice (Jun 21)5:32 AM57° ENE8:45 PM303° WNW72°15h 13m
September equinox (Sep 22)6:54 AM89° E7:05 PM271° W49°12h 11m
December solstice (Dec 21)7:31 AM122° ESE4:39 PM239° WSW25°9h 09m

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 startsSunriseGolden hour endsGolden hour startsSunsetBlue hour endsDaylight
January7:01 AM7:32 AM8:15 AM4:18 PM5:01 PM5:32 PM9h 29m
February6:34 AM7:03 AM7:42 AM5:01 PM5:40 PM6:08 PM10h 37m
March6:51 AM7:19 AM7:56 AM6:36 PM7:13 PM7:41 PM11h 54m
April5:58 AM6:27 AM7:04 AM7:10 PM7:47 PM8:16 PM13h 20m
May5:16 AM5:47 AM6:27 AM7:40 PM8:20 PM8:51 PM14h 32m
June4:58 AM5:32 AM6:14 AM8:01 PM8:43 PM9:17 PM15h 11m
July5:12 AM5:45 AM6:26 AM7:59 PM8:40 PM9:13 PM14h 55m
August5:46 AM6:15 AM6:54 AM7:29 PM8:08 PM8:38 PM13h 52m
September6:19 AM6:47 AM7:24 AM6:41 PM7:17 PM7:45 PM12h 30m
October6:51 AM7:19 AM7:57 AM5:48 PM6:26 PM6:54 PM11h 07m
November6:27 AM6:56 AM7:38 AM4:06 PM4:47 PM5:17 PM9h 51m
December6:56 AM7:27 AM8:12 AM3:53 PM4:37 PM5:09 PM9h 10m

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 Merrill Cave, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 4.3 hours on a moonless night), and the core peaks around 19° above the southern horizon. Our light-pollution model puts the sky at about Bortle 1 (excellent dark-sky site), which is excellent for astrophotography.

MonthCore visible (15th)HoursMax altitudeDirection
JanuaryBelow 10° in darkness—-3°—
FebruaryBelow 10° in darkness—10°—
March4:36 AM – 5:36 AM1.016°SE → SSE
April2:37 AM – 4:37 AM2.019°SE → S
May12:35 AM – 3:45 AM3.219°SE → S
June10:54 PM – 3:14 AM4.319°SSE → SSW
July10:44 PM – 1:54 AM3.219°S → SW
August9:53 PM – 11:53 PM2.019°S → SW
September8:52 PM – 9:52 PM1.016°SSW → SW
OctoberBelow 10° in darkness—10°—
NovemberBelow 10° in darkness—-1°—
DecemberBelow 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: 1 Bortle 1 — Excellent dark-sky site. The Milky Way casts faint shadows; zodiacal light and airglow are obvious. Modeled zenith brightness ≈ 21.91 mag/arcsec². Aurora needs roughly Kp 7.5+ 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 18% average cloud cover) and December as the cloudiest (66%). 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 (%)

JanFebMarAprMayJunJulAugSepOctNovDec
JanFebMarAprMayJunJulAugSepOctNovDec
High °F63637280899810310098907657
Low °F-11-29102229393929190-4
Precip. (in)3.53.93.62.41.90.80.20.20.51.63.05.0

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

  • Use manual focus with focus peaking in low light.
  • 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.
  • 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.

Permits, drones & access

National Park Service rules. Under federal law (54 U.S.C. 100905), still photography in National Park Service areas needs a permit only when it (1) takes place where members of the public are not allowed, (2) uses models, sets or props that are not part of the location's natural or cultural resources or administrative facilities, or (3) would cause the park to incur additional administrative costs to monitor the activity. Ordinary visitor and most landscape photography needs no permit. Commercial filming rules are separate and have changed in recent years — confirm current requirements with the park before a paid shoot.

Drones: Launching, landing or operating unmanned aircraft (drones) is prohibited in National Park Service units under a 2014 Superintendent's closure (36 CFR 1.5), except where a park has issued specific written approval. Flying from outside the boundary over park land can also violate park rules and disturb wildlife.

Nearby photo spots

Other locations within 25 km of Merrill Cave, closest first.

Campgrounds nearby (Recreation.gov)

FAQ

When is the best time to photograph Merrill Cave?
July has the clearest skies on average; june is best for the milky way core. For light, plan around the first and last hour of sun. Cave interiors stay at a constant temperature year-round; summer tours fill up, so book ahead.
What time is golden hour at Merrill Cave?
In October the evening golden hour starts around 5:48 PM and ends after sunset at about 6:26 PM; the morning golden hour lasts until about 7:57 AM. Use the live widget above for exact times on any date.
Where does the sun rise and set at Merrill Cave?
Sunrise azimuth ranges from about 57° in June to 122° in December; sunset ranges from 303° to 239°. See the sun-path diagram for the full arc.
Can you see the Milky Way from Merrill Cave?
Yes — the core is visible from March to September on moonless nights. The estimated sky quality is Bortle 1 (excellent dark-sky site).
Do you need a permit to photograph at Merrill Cave?
Personal still photography needs no permit in National Park Service areas unless you use models, sets or props, enter closed areas, or the shoot creates extra costs for the park. Drones are prohibited.
How far is Merrill Cave from Altamont?
About 55 km (34 mi) in a straight line; driving distance is usually longer, especially in mountain terrain.

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.