Montana · Mountain biking · Near Emigrant

Fs 643

2.0 mi
round trip
693 ft
climb
Singletrack
surface
Out and back
route
Jul–Sep
best months

Is FS 643 open right now?

Closure in the area

There's a closure order in Bozeman Ranger District. It doesn't name FS 643, so check the source for the area it covers (17 listed).

As of · Source: USFS · Bozeman Ranger District. Agencies don't list every closure — check before you go.

FS 643 is an easy mountain biking route in Montana's Custer Gallatin National Forest, within the Bozeman Ranger District. It's an out-and-back ride of about 4 miles with a one-way elevation gain of 241 feet, climbing from a low point of 7,887 feet to a high of 8,134 feet. The steepest stretch comes early, at about 0.19 miles in, with a 13% grade. Summer is the most comfortable time to ride. Typical averages from a nearby weather station at Big Sky run to highs around 78°F in July and 77°F in August, though that station sits roughly 1,500 feet below the route, so temperatures on the climb run cooler. Purdy Creek, a hike, is just 0.2 miles away, and Mica Mine Road, another mountain biking route, is 0.4 miles off. Little Bear Cabin and Spire Rock, both campgrounds, lie within about 3 miles.

Around this trail

Add any of these when you start a trip
  • Sleep close

    Fr3138-09 Wilson Ck Loop Trlhd

    Campground

    Campground · 0.6 mi from the trail

Places © OpenStreetMap contributors

More in Emigrant
  • Best time to go · Jul–Sep

    Best time to visit FS 643

    Best months: July–September. Best months have typical highs of 55–85 °F, lows of 30 °F or warmer (32 °F where the station doesn't record snow), at most one snowy day and no more than 12 wet days.

    1. Jan

      30° / 9°

      13 wet

    2. Feb

      34° / 9°

      11 wet

    3. Mar

      42° / 17°

      12 wet

    4. Apr

      48° / 23°

      11 wet

    5. May

      58° / 30°

      14 wet

    6. Jun

      67° / 36°

      14 wet

    7. Jul

      78° / 41°

      11 wet

    8. Aug

      77° / 39°

      11 wet

    9. Sep

      68° / 33°

      10 wet

    10. Oct

      53° / 25°

      10 wet

    11. Nov

      37° / 16°

      11 wet

    12. Dec

      27° / 9°

      14 wet

    Typical high / low (°F) and days with rain or snow, 1991–2020. Measured at Big Sky 2wnw, MT, 15.7 mi away at 6,590 ft. The station sits about 1,500 ft lower than this place, so expect it a little cooler here. This station doesn't record snowfall. Source: NOAA NCEI U.S. Climate Normals 1991–2020.

Map and trail data © OpenStreetMap contributors