Mark Twain Cave is a cave in Marion County, Missouri. The nearest town is Hannibal, about 3.2 km (2.0 mi) away (Mark Twain Cave lies SE of town).
Mark Twain Cave — originally McDowell's Cave — is a show cave located near Hannibal, Missouri. It was named for author Mark Twain. Twain lived in Hannibal from 1839 to 1853, age 4 to 17. It is the oldest operating show cave in the state, giving tours continuously since 1886. Along with nearby Cameron Cave, it became a registered National Natural Landmark in 1972, with a citation reading "Exceptionally good examples of the maze type of cavern development." The cave — as "McDougal's Cave" — plays an important role in Twain's 1876 novel The Adventures of Tom Sawyer and was renamed in honor of the author in 1880.From the Wikipedia article “Mark Twain Cave”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Mark Twain Cave the sunrise point swings a long way through the year: about 58° (ENE) at the June solstice and 121° (ESE) in late December. Sunset moves from 302° (WNW) in June to 240° (WSW) in December, and the midday sun climbs to 74° in summer but only 27° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:10 AM | 90° E | 7:18 PM | 271° W | 50° | 12h 08m |
| June solstice (Jun 21) | 5:38 AM | 58° ENE | 8:37 PM | 302° WNW | 74° | 14h 59m |
| September equinox (Sep 22) | 6:54 AM | 89° E | 7:04 PM | 271° W | 51° | 12h 11m |
| December solstice (Dec 21) | 7:24 AM | 121° ESE | 4:45 PM | 240° WSW | 27° | 9h 21m |
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 | 6:56 AM | 7:25 AM | 8:06 AM | 4:24 PM | 5:05 PM | 5:35 PM | 9h 40m |
| February | 6:31 AM | 6:59 AM | 7:36 AM | 5:04 PM | 5:42 PM | 6:10 PM | 10h 43m |
| March | 6:51 AM | 7:18 AM | 7:53 AM | 6:37 PM | 7:12 PM | 7:39 PM | 11h 55m |
| April | 6:01 AM | 6:29 AM | 7:05 AM | 7:07 PM | 7:43 PM | 8:11 PM | 13h 15m |
| May | 5:21 AM | 5:52 AM | 6:30 AM | 7:35 PM | 8:13 PM | 8:44 PM | 14h 22m |
| June | 5:05 AM | 5:38 AM | 6:18 AM | 7:55 PM | 8:36 PM | 9:08 PM | 14h 58m |
| July | 5:19 AM | 5:51 AM | 6:30 AM | 7:54 PM | 8:33 PM | 9:05 PM | 14h 43m |
| August | 5:49 AM | 6:18 AM | 6:55 AM | 7:26 PM | 8:03 PM | 8:32 PM | 13h 45m |
| September | 6:20 AM | 6:47 AM | 7:23 AM | 6:40 PM | 7:16 PM | 7:43 PM | 12h 29m |
| October | 6:49 AM | 7:16 AM | 7:53 AM | 5:51 PM | 6:27 PM | 6:55 PM | 11h 11m |
| November | 6:22 AM | 6:51 AM | 7:30 AM | 4:11 PM | 4:51 PM | 5:20 PM | 10h 00m |
| December | 6:50 AM | 7:20 AM | 8:03 AM | 4:00 PM | 4:43 PM | 5:13 PM | 9h 23m |
Local time (America/Chicago), 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 Mark Twain Cave, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 4.8 hours on a moonless night), and the core peaks around 21° above the southern horizon. Our light-pollution model puts the sky at about Bortle 5 (suburban sky), so expect visible sky glow; drive away from towns for better results.
| Month | Core visible (15th) | Hours | Max altitude | Direction |
|---|---|---|---|---|
| January | Below 10° in darkness | — | -3° | — |
| February | 5:12 AM – 5:22 AM | 0.2 | 11° | SE → SE |
| March | 4:22 AM – 5:42 AM | 1.3 | 18° | SE → SSE |
| April | 2:20 AM – 4:50 AM | 2.5 | 21° | SE → S |
| May | 12:23 AM – 3:53 AM | 3.5 | 21° | SE → S |
| June | 10:37 PM – 3:27 AM | 4.8 | 21° | SE → SSW |
| July | 10:29 PM – 2:09 AM | 3.7 | 21° | S → SW |
| August | 9:44 PM – 12:04 AM | 2.3 | 21° | S → SW |
| September | 8:47 PM – 10:07 PM | 1.3 | 18° | SSW → SW |
| October | 7:57 PM – 8:07 PM | 0.2 | 12° | 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: 5 Bortle 5 — Suburban sky. The Milky Way is weak near the horizon and washed out overhead; long exposures pick up a sky glow. Modeled zenith brightness ≈ 19.56 mag/arcsec². Aurora needs roughly Kp 7.0+ 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 42% average cloud cover) and February as the cloudiest (65%). 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 | 67 | 75 | 79 | 87 | 93 | 107 | 108 | 107 | 103 | 93 | 80 | 72 |
| Low °F | -16 | -9 | -3 | 19 | 33 | 46 | 51 | 48 | 36 | 20 | 9 | -10 |
| Precip. (in) | 1.8 | 2.2 | 2.9 | 4.2 | 4.8 | 4.8 | 4.1 | 3.8 | 3.4 | 3.4 | 2.4 | 2.2 |
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.
- 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 Mark Twain Cave, closest first.
Campgrounds nearby (Recreation.gov)
FAQ
When is the best time to photograph Mark Twain Cave?
What time is golden hour at Mark Twain Cave?
Where does the sun rise and set at Mark Twain Cave?
Can you see the Milky Way from Mark Twain Cave?
Do you need a permit to photograph at Mark Twain Cave?
How far is Mark Twain Cave from Hannibal?
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.