A popular winter recreation area in the Eastern Sierra is closed to snowmobiling until further notice.
That’s according to the U.S. Forest Service which on Tuesday closed the Bridgeport Winter Recreation Area.
It’s among the earliest closing dates on record for the area, according to Adrianne Thatcher, recreation staff officer for the Bridgeport Ranger District in the Humboldt-Toiyabe National Forest. If the area doesn't reopen 2018 would be its shortest season on record.
“Leavitt Lake Road was down to bare dirt,” said Thatcher of the road that intersects with California State Route 108 at about 8,400 feet in elevation. “We were having temperatures in the low 50s above 9,000 feet up at the (Sonora) pass.”
At Hope Valley there is little to no snow and at Tahoe Meadows the snowpack is thin enough that riders would risk damaging the ground with machines, which could lead to a fine.
The area typically opens to snowmobiles when the snow depth reaches 24 inches at Leavitt Lake Road and 108. It’s closed when the snowpack decreases to 12 inches.
The depth requirements prevent machines from damaging the ground or harming wildlife, such as the threatened Yosemite toad.
“They require a two-foot snow base in order not to be smooshed,” Thatcher said.
The Leavitt Lake Snotel snow measuring device shows the snowpack is 48 percent of the median level. It’s the fourth-lowest reading for the date since 1990. The lowest reading was in 1991 and the next two lowest were 2012 and 2014.
Thin snowpack is widespread throughout the Sierra Nevada. In early February the snowpack was near the lowest ever recorded below 8,000 feet in the Reno area. At Donner Summit it was third lowest since 1922 and Ward Creek near Tahoe City was third lowest since 1954.
The Tahoe Basin snowpack was 26 percent of normal on Feb. 5, the Truckee River Basin was at 44 percent and the Walker Basin 41 percent.
While snowpack is consistent with near-record drought conditions, many of the region’s urban water users will remain insulated from potential drought by virtue of record precipitation during the winter of 2016-17 that filled storage reservoirs.
Conditions are also consistent with scientific observations on human-induced global warming. Research shows the warming is driving the Sierra snowline higher and increasing the percentage of winter precipitation that falls as rain instead of snow.