Glassford Peak — a mountain peak in Custer County, Idaho at about 3,522 m (11,555 ft) above sea level — is a lesser-known subject for landscape photographers. It sits roughly 26 km (16 mi) NNW of Sun Valley.
Glassford Peak, at 11,602 feet (3,536 m) above sea level is the third highest peak in the Boulder Mountains of Idaho. Located in the Hemingway–Boulders Wilderness of Sawtooth National Recreation Area and Custer County, Glassford Peak is about 0.55 miles (890 m) north of the Blaine County border. It is the 39th highest peak in Idaho. The peak is most easily accessed from south of Idaho State Highway 75 between Stanley and Challis. However, it can also be accessed from State Highway 75 north of Ketchum.From the Wikipedia article “Glassford Peak”, licensed under CC BY-SA 4.0.
Sunrise & sunset directions
At Glassford Peak the sunrise point swings a long way through the year: about 56° (NE) at the June solstice and 123° (ESE) in late December. Sunset moves from 305° (NW) in June to 238° (WSW) in December, and the midday sun climbs to 70° in summer but only 23° in winter.
| Date | Sunrise | Azimuth | Sunset | Azimuth | Noon sun | Daylight |
|---|---|---|---|---|---|---|
| March equinox (Mar 20) | 7:42 AM | 90° E | 7:50 PM | 271° W | 46° | 12h 09m |
| June solstice (Jun 21) | 5:56 AM | 56° NE | 9:25 PM | 305° NW | 70° | 15h 29m |
| September equinox (Sep 22) | 7:26 AM | 89° E | 7:37 PM | 271° W | 46° | 12h 11m |
| December solstice (Dec 21) | 8:10 AM | 123° ESE | 5:04 PM | 238° WSW | 23° | 8h 54m |
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
Summits catch first and last light — alpenglow can turn rock pink or orange minutes before sunrise and after sunset while valleys stay in shadow.
| Month (15th) | Blue hour starts | Sunrise | Golden hour ends | Golden hour starts | Sunset | Blue hour ends | Daylight |
|---|---|---|---|---|---|---|---|
| January | 7:38 AM | 8:10 AM | 8:55 AM | 4:41 PM | 5:26 PM | 5:58 PM | 9h 16m |
| February | 7:08 AM | 7:38 AM | 8:18 AM | 5:28 PM | 6:08 PM | 6:38 PM | 10h 30m |
| March | 7:22 AM | 7:51 AM | 8:29 AM | 7:06 PM | 7:44 PM | 8:13 PM | 11h 53m |
| April | 6:25 AM | 6:55 AM | 7:34 AM | 7:43 PM | 8:22 PM | 8:52 PM | 13h 26m |
| May | 5:40 AM | 6:13 AM | 6:55 AM | 8:16 PM | 8:57 PM | 9:31 PM | 14h 44m |
| June | 5:19 AM | 5:56 AM | 6:40 AM | 8:39 PM | 9:23 PM | 9:59 PM | 15h 27m |
| July | 5:35 AM | 6:10 AM | 6:53 AM | 8:36 PM | 9:19 PM | 9:54 PM | 15h 09m |
| August | 6:12 AM | 6:43 AM | 7:23 AM | 8:04 PM | 8:44 PM | 9:15 PM | 14h 01m |
| September | 6:49 AM | 7:18 AM | 7:56 AM | 7:12 PM | 7:50 PM | 8:19 PM | 12h 32m |
| October | 7:24 AM | 7:53 AM | 8:32 AM | 6:16 PM | 6:56 PM | 7:25 PM | 11h 03m |
| November | 7:02 AM | 7:34 AM | 8:17 AM | 4:30 PM | 5:13 PM | 5:44 PM | 9h 40m |
| December | 7:33 AM | 8:06 AM | 8:54 AM | 4:14 PM | 5:02 PM | 5:35 PM | 8h 55m |
Local time (America/Boise), 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 Glassford Peak, the Milky Way core is visible in a dark sky from March through September. June gives the longest window (about 3.7 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 | — | -4° | — |
| February | Below 10° in darkness | — | 8° | — |
| March | 5:31 AM – 6:11 AM | 0.7 | 14° | SSE → SSE |
| April | 3:27 AM – 5:07 AM | 1.7 | 16° | SSE → S |
| May | 1:32 AM – 4:02 AM | 2.5 | 17° | SSE → S |
| June | 11:48 PM – 3:28 AM | 3.7 | 17° | SSE → SSW |
| July | 11:34 PM – 2:04 AM | 2.5 | 17° | S → SSW |
| August | 10:36 PM – 12:06 AM | 1.5 | 16° | S → SSW |
| September | 9:29 PM – 9:59 PM | 0.5 | 13° | SSW → SSW |
| October | Below 10° in darkness | — | 8° | — |
| November | Below 10° in darkness | — | -2° | — |
| 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 ≈ 21.91 mag/arcsec². Aurora needs roughly Kp 6.0+ 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 30% average cloud cover) and December as the cloudiest (64%). 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 | 45 | 50 | 63 | 75 | 86 | 94 | 98 | 96 | 91 | 82 | 64 | 45 |
| Low °F | -21 | -16 | -8 | 11 | 19 | 26 | 35 | 33 | 24 | 6 | -29 | -18 |
| Precip. (in) | 2.2 | 1.9 | 2.2 | 1.7 | 1.7 | 1.1 | 0.5 | 0.6 | 1.0 | 1.4 | 1.8 | 2.9 |
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 mountain peak
- Clouds around the summit add drama — a clear blue sky is often the least interesting condition.
- Photograph the peak from a lake, meadow or ridge at sunrise when the face that looks east lights up first.
- Long lenses compress ridgelines; shoot the peak from several miles away to make it look massive.
- Afternoon thunderstorms are common in summer at high elevations — plan summit hikes for early morning.
- Snow on the summit holds detail best when you expose for the highlights and lift shadows later.
- Check road and trail conditions with the managing agency before you go.
Season: Early summer keeps snow on the peaks with green valleys below; autumn adds aspen or larch color in many ranges.
Suggested gear: Telephoto lens, Lightweight tripod, Warm layers, Microspikes in shoulder seasons. Work out exposures with the depth of field, ND filter and NPF rule calculators.
Nearby photo spots
Other locations within 25 km of Glassford Peak, closest first.
Wilderness Area
Mountain Peak
Mountain Peak
Wilderness Area
Wilderness Area
Mountain Pass
Scenic Viewpoint
Mountain Peak
Mountain PeakCampgrounds nearby (Recreation.gov)
- Caribou Campground11.1 km (6.9 mi) · reservable
- Murdock Campground13.0 km (8.1 mi) · reservable
- Wood River Group Overnight Area (Tent Only)13.4 km (8.3 mi) · reservable
- North Fork (Id)14.5 km (9.0 mi) · reservable
- Easley Campground15.4 km (9.6 mi) · reservable
FAQ
When is the best time to photograph Glassford Peak?
What time is golden hour at Glassford Peak?
Where does the sun rise and set at Glassford Peak?
Can you see the Milky Way from Glassford Peak?
Do you need a permit to photograph at Glassford Peak?
How far is Glassford Peak from Sun Valley?
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.