Blue Grotto Cave — a cave in Siskiyou County, California — is a popular subject for landscape photographers. It lies in or next to Lava Beds National Monument, so park hours, fees and rules apply. The nearest town is Altamont, about 58 km (36 mi) away (Blue Grotto Cave lies SSE of town).
From the National Park Service
Blue Grotto Cave (1,541 ft / 470 m) One of the "Moderately Challenging Caves." This cave is named for the pale blue-gray portions of the ceiling inside the “Blue Grotto”. The ceilings are high throughout this cave, but the floors are rough.
Typically Closed: mid-April to mid-October.
Length: 1,541 feet. You can walk completely upright on main path. Cave has stairs/steps. Cave has a relatively "smooth" path. Distance from visitor center: Cave Loop
The caves found here were created by flows of smooth lava 10,500 to 65,000 years ago. As the lava cooled, caves formed and created homes for unique cave life to thrive. These fantastic underground worlds can be visited on your own or by guided tour in the summer. Please “take only pictures, leave only footprints” so others have a chance to discover what you have during your trip. Certain caves are closed to protect bats. Please check with a ranger for current closures.
Text: National Park Service (public domain) — nps.gov.
Sunrise & sunset directions
At Blue Grotto 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.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:10 AM | 90° E | 7:18 PM | 271° W | 48° | 12h 08m |
| June solstice (Jun 21) | 5:32 AM | 57° ENE | 8:45 PM | 303° WNW | 72° | 15h 12m |
| September equinox (Sep 22) | 6:54 AM | 89° E | 7:05 PM | 271° W | 49° | 12h 11m |
| December solstice (Dec 21) | 7:31 AM | 122° ESE | 4:39 PM | 239° WSW | 25° | 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 starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:01 AM | 7:31 AM | 8:14 AM | 4:18 PM | 5:01 PM | 5:31 PM | 9h 29m |
| February | 6:34 AM | 7:02 AM | 7:41 AM | 5:01 PM | 5:40 PM | 6:08 PM | 10h 37m |
| March | 6:51 AM | 7:19 AM | 7:55 AM | 6:36 PM | 7:13 PM | 7:41 PM | 11h 54m |
| April | 5:58 AM | 6:26 AM | 7:04 AM | 7:09 PM | 7:47 PM | 8:16 PM | 13h 20m |
| May | 5:15 AM | 5:47 AM | 6:27 AM | 7:39 PM | 8:19 PM | 8:51 PM | 14h 32m |
| June | 4:58 AM | 5:32 AM | 6:14 AM | 8:01 PM | 8:43 PM | 9:17 PM | 15h 11m |
| July | 5:12 AM | 5:45 AM | 6:26 AM | 7:59 PM | 8:40 PM | 9:13 PM | 14h 55m |
| August | 5:45 AM | 6:15 AM | 6:54 AM | 7:29 PM | 8:08 PM | 8:37 PM | 13h 52m |
| September | 6:19 AM | 6:47 AM | 7:24 AM | 6:41 PM | 7:17 PM | 7:45 PM | 12h 30m |
| October | 6:51 AM | 7:19 AM | 7:57 AM | 5:48 PM | 6:26 PM | 6:54 PM | 11h 07m |
| November | 6:26 AM | 6:56 AM | 7:38 AM | 4:06 PM | 4:47 PM | 5:17 PM | 9h 51m |
| December | 6:56 AM | 7:27 AM | 8:12 AM | 3:52 PM | 4:37 PM | 5:09 PM | 9h 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 Blue Grotto 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.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -3° | — |
| February | Below 10° in darkness | — | 10° | — |
| March | 4:36 AM – 5:36 AM | 1.0 | 16° | SE → SSE |
| April | 2:37 AM – 4:37 AM | 2.0 | 19° | SE → S |
| May | 12:35 AM – 3:45 AM | 3.2 | 19° | SE → S |
| June | 10:54 PM – 3:14 AM | 4.3 | 19° | SSE → SSW |
| July | 10:44 PM – 1:54 AM | 3.2 | 19° | S → SW |
| August | 9:53 PM – 11:53 PM | 2.0 | 19° | S → SW |
| September | 8:52 PM – 9:52 PM | 1.0 | 16° | SSW → SW |
| October | Below 10° in darkness | — | 10° | — |
| November | Below 10° in darkness | — | -1° | — |
| 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: 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 (%)
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High °F | 63 | 63 | 72 | 80 | 89 | 98 | 103 | 100 | 98 | 90 | 76 | 57 |
| Low °F | -11 | -2 | 9 | 10 | 22 | 29 | 39 | 39 | 29 | 19 | 0 | -4 |
| Precip. (in) | 3.5 | 3.9 | 3.6 | 2.4 | 1.9 | 0.8 | 0.2 | 0.2 | 0.5 | 1.6 | 3.0 | 5.0 |
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
- 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.
- Follow White-nose Syndrome decontamination rules where posted to protect bats.
- Scout in daylight if you plan to shoot at night or before sunrise.
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 Blue Grotto Cave, closest first.
Natural ArchNatural ArchNatural ArchNatural ArchNatural ArchNatural Arch
CaveNatural ArchNatural ArchCampgrounds nearby (Recreation.gov)
- Indian Well Campground1.4 km (0.9 mi)
- Medicine Lake Recreation Area14.8 km (9.2 mi) · reservable
- Little Mt. Hoffman Lookout18.8 km (11.7 mi) · reservable
FAQ
When is the best time to photograph Blue Grotto Cave?
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Sources
Location data: National Park Service. 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.