Fort Union Trading Post National Historic Site is a National Historic Site in Montana, North Dakota. This guide combines the park's official information with computed sunrise, sunset and Milky Way times, satellite climate data and nearby photo locations.
Sunrise, sunset & golden hour
At Fort Union Trading Post the sunrise point swings a long way through the year: about 53° (NE) at the June solstice and 126° (SE) in late December. Sunset moves from 308° (NW) in June to 235° (SW) in December, and the midday sun climbs to 65° in summer but only 19° in winter.
| Month (15th) | Sunrise | Golden hour ends | Golden hour starts | Sunset | Sunset az. | Daylight |
|---|---|---|---|---|---|---|
| January | 8:42 AM | 9:32 AM | 4:40 PM | 5:31 PM | 239° | 8h 49m |
| February | 8:04 AM | 8:48 AM | 5:35 PM | 6:19 PM | 252° | 10h 15m |
| March | 8:10 AM | 8:51 AM | 7:21 PM | 8:02 PM | 268° | 11h 51m |
| April | 7:07 AM | 7:49 AM | 8:04 PM | 8:46 PM | 286° | 13h 39m |
| May | 6:18 AM | 7:04 AM | 8:43 PM | 9:29 PM | 300° | 15h 10m |
| June | 5:57 AM | 6:46 AM | 9:09 PM | 9:58 PM | 308° | 16h 01m |
| July | 6:13 AM | 7:00 AM | 9:05 PM | 9:52 PM | 304° | 15h 40m |
| August | 6:52 AM | 7:35 AM | 8:28 PM | 9:11 PM | 292° | 14h 19m |
| September | 7:34 AM | 8:15 AM | 7:30 PM | 8:11 PM | 276° | 12h 36m |
| October | 8:16 AM | 8:58 AM | 6:27 PM | 7:09 PM | 258° | 10h 53m |
| November | 8:03 AM | 8:52 AM | 4:32 PM | 5:20 PM | 243° | 9h 17m |
| December | 8:40 AM | 9:34 AM | 4:11 PM | 5:04 PM | 235° | 8h 24m |
Computed for the park's reference point (48.0008, -104.0375); large parks span several minutes of difference.
Milky Way & dark skies
From Fort Union Trading Post, the Milky Way core is visible in a dark sky from April through July. June gives the longest window (about 1.3 hours on a moonless night), and the core peaks around 13° 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 |
|---|---|---|---|
| January | Not visible in darkness | — | — |
| February | Not visible in darkness | — | — |
| March | Not visible in darkness | — | — |
| April | 4:32 AM – 5:02 AM | 0.5 | 12° |
| May | 2:34 AM – 3:44 AM | 1.2 | 13° |
| June | 1:13 AM – 2:33 AM | 1.3 | 13° |
| July | 12:39 AM – 1:39 AM | 1.0 | 13° |
| August | 11:17 PM – 11:37 PM | 0.3 | 11° |
| September | Not visible in darkness | — | — |
| October | Not visible in darkness | — | — |
| November | Not visible in darkness | — | — |
| December | Not visible in darkness | — | — |
1 Estimated Bortle 1 — Excellent dark-sky site. The Milky Way casts faint shadows; zodiacal light and airglow are obvious.
Weather & best time to visit
Weather in western North Dakota can be harsh, with extremes in temperature and sudden, violent storms. Be prepared for rapidly changing conditions. Summers are warm with average high temperatures in the 80s-90s May through September. Winters are cold with average lows in the single digits December through February. Wind is considerable year-round. Conditions can change quickly. Travelers should be aware of the potential for violent thunderstorms in the summer and the possibility of blizzards.
Weather overview: National Park Service.
Long-term NASA satellite data for this area show July as the clearest month (about 44% average cloud cover) and December as the cloudiest (70%). 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 (%)
Average high (°F)
Photography permits, drones & fees
Permits. 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.
Getting there
Located on North Dakota Highway 1804 right at the Montana and North Dakota state line. From Williston, ND, approximately 25 miles to the southwest via ND Highways 2 & 1804. From Sidney, MT, approximately 25 miles to the northeast, via MT Highways 200 & 58. Commercial flights and rental cars are available in both Williston, ND and Sidney, MT. Amtrak passenger train service and rental cars are available in Williston, ND.
Directions: National Park Service.
Activities
- Arts and Culture
- Craft Demonstrations
- Cultural Demonstrations
- Guided Tours
- Self-Guided Tours - Walking
- Living History
- Reenactments
- Historic Weapons Demonstration
- Junior Ranger Program
- Park Film
- Museum Exhibits
- Shopping
- Bookstore and Park Store
- Gift Shop and Souvenirs
