Peter Sinks, 7 August, 2022

Thirteen hikers met at Smith’s Marketplace and carpooled up Logan Canyon to the Beaver Junction Picnic Area & Winter Trailhead  parking lot. After crossing the highway, we started up the Stump Hollow trail, winding our way through subalpine forest and mountain mahogany communities, and down into an expansive mountain sagebrush community, eventually reaching Peter Sinks. This sink has registered some of the coldest winter temperatures in the U.S. over the years. A thermometer was inserted into the opening in an adjacent sink bottom, and measured a temperature of 46 ºF, while the ambient air temperature was 70 ºF.  Several individuals hiked a short distance over to a weather station along the ridge above the sink area.

We had lunch at the adjacent sink where temperatures were measured, and headed back on the same trail to the parking area. While walking out and back on the trail, we encountered several mountain bikers and a few other hikers. We also stopped several times to identify plant species, discuss geological features, and view distant peaks and basins in the Logan Canyon area.

Trip Summary:
  • Thirteen hikers: Brent L., Brent J., Jane E., Jane P., Dave P., Dave W., Alex, Joan, Kamren, Laurel (and her dog Zinnia), Ralph, April, and Chris (leader).
  • Started hiking at 8:45 am; lunch from noon to 12:40 pm; completed hike at 3:10 pm.
  • Great hiking conditions: bluebird day, mild temperatures, little to no wind, and no bugs.
  • Approximately 10.5 miles and 1,600 feet of elevation gain.

Thanks to Chris for the narrative and photos, Ralph, Dave P., and Jane E. for photos and Dave W. for photos and GPS data.

At the Stump Hollow trailhead, the beginning and end of our hike

Motor vehicles are not allowed, including "E-Bikes", but we saw fresh motorcycle tracks, regardless

We followed the lesser-traveled "official" route
Zinnia drank from a trailside spring

Major peaks of the Bear River Range were clearly visible as we hiked

A conversation on the trail
A cairn near the north end of Peter Sinks

Cold air concentrates in Peter Sinks, resulting in an "inverted treeline", with a treeless area below, a transition zone of krummholtz (stunted and distorted trees) and normal trees above.  This sequence is opposite the normal situation.

Looking northward over Peter Sinks

Several hikers went to the Peter Sinks weather station Lunch near one of the sinks
Mountain bikers rode by on a ridge as we ate
We measured the temperature in one of the sinks

. 46 ºF at the bottom of the sink It was about 70 ºF at Peter Sinks, but overnight the wind stopped and the temperature dropped to freezing

Showy fleabane and a fritillary butterfly
Red elderberry

Our GPS track shows about 10.5 miles and 1600 feet of ascent.
You can look at our route using Google Earth or download our GPS file.