Isa Lake is a lake in Teton County, Wyoming at about 2,529 m (8,297 ft) above sea level. It lies in or next to Yellowstone National Park, so park hours, fees and rules apply. The nearest town is West Yellowstone, about 39 km (24 mi) away (Isa Lake lies SE of town).
Isa Lake is located in Yellowstone National Park, in the U.S. state of Wyoming. The lake straddles the continental divide at Craig Pass. Hiram M. Chittenden became the first known European to sight the lake in 1891, while searching for the best routes connecting Old Faithful and the West Thumb Geyser Basin. Chittenden named the lake after Miss Isabel Jelke, from Cincinnati, though it is not clear why. Isa Lake is believed to be one of the few natural lakes in the world which drain to two different oceans, another being Wollaston Lake. The east side of the lake drains by way of the Lewis River to the Pacific Ocean and the west side of the lake drains by way of the Firehole River to the Gulf of Mexico. The lake is easy to visit as it is adjacent to the road that now connects the Old Faithful and West Thumb geysers basins, on what is known as the "lower loop" of the figure-eight roadway...From the Wikipedia article “Isa Lake”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Isa Lake 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) | 7:27 AM | 90° E | 7:35 PM | 271° W | 45° | 12h 09m |
| June solstice (Jun 21) | 5:39 AM | 55° NE | 9:12 PM | 305° NW | 69° | 15h 33m |
| September equinox (Sep 22) | 7:11 AM | 89° E | 7:22 PM | 271° W | 46° | 12h 11m |
| December solstice (Dec 21) | 7:57 AM | 123° ESE | 4:47 PM | 237° WSW | 22° | 8h 50m |
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
Lakes reflect best in calm air — usually the first hour after sunrise, before breezes ripple the surface.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:24 AM | 7:56 AM | 8:42 AM | 4:23 PM | 5:09 PM | 5:42 PM | 9h 13m |
| February | 6:54 AM | 7:24 AM | 8:05 AM | 5:11 PM | 5:52 PM | 6:22 PM | 10h 28m |
| March | 7:07 AM | 7:36 AM | 8:15 AM | 6:51 PM | 7:29 PM | 7:58 PM | 11h 53m |
| April | 6:09 AM | 6:40 AM | 7:19 AM | 7:28 PM | 8:07 PM | 8:38 PM | 13h 28m |
| May | 5:23 AM | 5:56 AM | 6:38 AM | 8:02 PM | 8:44 PM | 9:18 PM | 14h 47m |
| June | 5:02 AM | 5:39 AM | 6:23 AM | 8:25 PM | 9:10 PM | 9:47 PM | 15h 31m |
| July | 5:18 AM | 5:53 AM | 6:36 AM | 8:22 PM | 9:06 PM | 9:41 PM | 15h 13m |
| August | 5:55 AM | 6:27 AM | 7:07 AM | 7:50 PM | 8:30 PM | 9:01 PM | 14h 03m |
| September | 6:33 AM | 7:03 AM | 7:41 AM | 6:57 PM | 7:35 PM | 8:05 PM | 12h 33m |
| October | 7:09 AM | 7:39 AM | 8:18 AM | 6:00 PM | 6:40 PM | 7:09 PM | 11h 02m |
| November | 6:49 AM | 7:20 AM | 8:04 AM | 4:13 PM | 4:57 PM | 5:28 PM | 9h 37m |
| December | 7:20 AM | 7:53 AM | 8:41 AM | 3:57 PM | 4:45 PM | 5:18 PM | 8h 52m |
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 Isa Lake, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 3.5 hours on a moonless night), and the core peaks around 17° 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 | — | 8° | — |
| March | 5:17 AM – 5:57 AM | 0.7 | 13° | SSE → SSE |
| April | 3:14 AM – 4:44 AM | 1.5 | 16° | SSE → S |
| May | 1:21 AM – 3:41 AM | 2.3 | 17° | SSE → S |
| June | 11:39 PM – 3:09 AM | 3.5 | 17° | SSE → SSW |
| July | 11:24 PM – 1:44 AM | 2.3 | 17° | S → SSW |
| August | 10:23 PM – 11:43 PM | 1.3 | 16° | SSW → SSW |
| September | 9:15 PM – 9:45 PM | 0.5 | 13° | 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 ≈ 21.93 mag/arcsec². Aurora needs roughly Kp 5.5+ 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 39% average cloud cover) and February as the cloudiest (77%). 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 | 33 | 32 | 51 | 64 | 73 | 80 | 90 | 90 | 82 | 72 | 53 | 33 |
| Low °F | -32 | -34 | -21 | -10 | 6 | 22 | 29 | 28 | 18 | -9 | -23 | -32 |
| Precip. (in) | 3.1 | 3.1 | 3.0 | 3.2 | 3.1 | 2.8 | 1.4 | 1.6 | 2.0 | 2.6 | 3.1 | 3.5 |
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 lake
- Mist often lifts off lakes on cold mornings after warm days, especially in autumn.
- Include shoreline rocks, reeds or a log as foreground to give the reflection depth.
- Expose for the brighter sky; reflections are typically half a stop to a stop darker.
- After sunset, long exposures smooth wind ripples into glass.
- Shoot RAW to keep the most latitude for high-contrast sunrise and sunset scenes.
Season: Autumn mornings bring mist and fall color; high-elevation lakes are usually ice-free only from early summer to mid-autumn.
Suggested gear: Tripod, Circular polarizer, Wide-angle lens, Waterproof boots. 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 Isa Lake, closest first.
Mountain Pass
Volcano
Rock Formation
Waterfall
Hot Spring
Lake
Hot Spring
Hot Spring
Hot SpringCampgrounds nearby (Recreation.gov)
FAQ
When is the best time to photograph Isa Lake?
What time is golden hour at Isa Lake?
Where does the sun rise and set at Isa Lake?
Can you see the Milky Way from Isa Lake?
Do you need a permit to photograph at Isa Lake?
How far is Isa Lake from West Yellowstone?
Sources
Location data: Wikidata, USGS GNIS / GeoNames, 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.