Spring Road Clearing

A snow plow clears snow near the Devastated Area.

 

Learn and Explore

The 30-mile Lassen Volcanic National Park Highway traverses avalanche-prone slopes with up to 2,000 foot drops and can hold a snowpack up to 40 feet deep. Snow clearing operations usually begin in March or April and continues for about two months before the highway is entirely open.

Once a section of road is cleared, it remains closed to vehicles until the last layer of snow and ice melts and all road preparations (e.g. signs, shoulder grading) are complete. At that time, the section may open to vehicles. Visitors can enjoy hiking or biking sections of the highway once they are cleared of snow and before they open to vehicles.

• Current Status of Roads
• Directions for Travel Around the Park
• Oversnow Route Conditions
• Hike and Bike the Highway
• Snowpack

 

On This Page Navigation

 

Map of road status and snow clearing progress as of 4/9/2021.

 

Road Clearing Operator Log

Log updates are posted when reports are received from road crew members. The latest update may not reflect the current status. The road crew works Monday through Thursday, 10 hours per day.

April 9, 2020 - We ended our week at Emerald Lake, just below Bumpass Hell Trailhead parking area. That gives us a total of 5.5 miles for the first week. Caltrans will be starting to assist with the large parking lots Tuesday.

April 5, 2021 - Crew completed clearing between Kohm Yah-mah-nee Visitor Center and Windy Point (0.5 mile beyond Sulphur Works). Snow depth is lower-than-average at 6 to 8 feet.

March 23, 2021 - Clearing to Devastated Area was completed today. hikers and bicyclists can enjoy the cleared road until it opens to vehicles when conditions permit (see map above for current status). Thank you to CalTrans in assisting with steady snow removal and re-clearing the new snow that fell March 8. Road crew will transport equipment to the Southwest Entrance in preparation to begin clearing operations either around March 31. There is approximately 8 feet of snow on the road in the Southwest Area. The clearing process goes more slowly in this area due to the steep slopes, avalanches, hairpin turns, and heavy snow drifts.

March 19, 2021 - Road crew has cleared the park highway between Loomis Plaza and Hot Rock (6.7 miles). Progress was slower than usual due to equipment issues and new snowfall. Road crew will continue clearing to Devastated Area on Monday, 3/22.

March 3, 2021 - Road crews have completed initial snow clearing operations along the Manzanita Lake Campground Road and in the Manzanita Lake Campground (opens 5/21). CalTrans has cleared the park highway between Loomis Plaza and Sunflower Flat (2.5 miles) and will continue towards Devastated Area (10 miles). Once the highway is cleared to Devastated Area, road crews will begin clearing in the Southwest Area. This could possibly occur as early as the last week of March, depending on weather and equipment.

 

 

Top: Winter road conditions at the Southwest Entrance, people walking on the park highway, a cleared section of highway below Lassen Peak.

When Will the Highway Open to Through Traffic?

Road crews begin clearing snow from the park highway in March or April, depending on snow depth and weather forecasts. It is not possible to predict when the highway will open to through traffic, because weather and other delays can affect the clearing process significantly. A chart below provides opening and closing dates of the park highway since 1980. The park does not clear snow from Butte Lake, Warner Valley, or Juniper Lake Roads. The paved sections of Warner Valley and Juniper Lake Roads are maintained by Plumas County and are usually not plowed.

Snow clearing operations occur in the following order:

1. Manzanita Lake Area between Loomis Plaza and Devastated Area (10 miles).
2. Southwest Area between Kohm Yah-mah-nee Visitor Center and Lassen Peak (8 miles).
3. Devastated Area to Lassen Peak (12 miles).

 

A bulldozer pushes snow off a steep slope below Emerald Lake on the park highway.

What's the Delay?

Clearing the park highway is no quick or easy undertaking! Snow accumulates on the 30-mile park highway throughout the winter season (typically November through April). Snow depth can reach up to 30 feet at the highest elevations, with drifts occasionally reach as high as 40 feet. The road clearing process can take up to three months due to numerous factors including:

• Heavy snowpack with deeper snowdrifts in some areas

• Trees and boulders that have fallen across the road and been buried in the snow

• Rockslides over the highway when the snow begins to melt

• Snow avalanches over cleared sections of the highway

• Snow storms (and additional accumulation) during the operations

• Snow removal in parking areas

• Road and road shoulder repairs

• Lingering ice once snow is cleared
• Equipment repair

 

Duration:

4 minutes, 27 seconds

See how park road crews clear snow from the park highway in a two-month long process each spring.

 

Spring Road Opening Dates - 1980 to Present

Year	Date plowing began from southwest	Date road opened	April 1 Snow Depth at Lake Helen (8,200' elevation)	Date road closed
1980	April 20	May 29	231" / 19.3'	November 21
1981	April 20	May 21	149" / 12.5'	November 3
1982	April 19	June 18	266" / 22.2'	October 25
1983	April 18	July 2	331" / 27.6'	November 10
1984	April 23	June 4	175" / 14.6'	October 28
1985	April 14	May 18	163" / 13.6'	October 21
1986	April 7	June 7	195" / 16.3'	November 24
1987	April 20	May 15	138" / 11.6'	November 13
1988	April 2	May 20	98" / 8.2'	November 7
1989	April 3	June 6	223" / 18.6'	October 23
1990	April 1	April 28	106" / 8.9'	November 14
1991	April 7	May 24	151" / 12.6'	October 22
1992	April 6	May 14	127" / 10.6'	October 29
1993	April 12	June 28	225" / 18.8'	November 10
1994	April 3	May 20	101" / 8.4'	November 7
1995	March 19	July 21	287" / 23.9'	November 21
1996	April 1	June 12	171" / 14.3'	October 18
1997	April 7	June 5	135" / 11.3'	November 14
1998	April 5	July 12	250" / 20.9'	November 10
1999	April 12	June 11	194" / 16.2'	November 19
2000	April 3	June 2	178" / 14.9'	November 17
2001	April 2	May 10	109" / 9.1'	November 15
2002	April 1	May 22	166" / 13.9'	November 13
2003	March 26	May 23	185" / 15.5'	November 7
2004	March 11	May 27	187" / 15.6'	October 28
2005	April 4	June 2	173" / 14.5'	November 8
2006	April 3	July 6	266" / 22.2'	November 11
2007	April 2	May 18	112" / 9.3'	December 6
2008	March 31	May 18	132" / 11'	December 12
2009	April 13	June 4	146" / 12.2'	November 18
2010	April 19	July 8	169" / 14.1'	October 23
2011	April 19	July 16	242" / 20.2'	November 22
2012	April 21	June 1	145" / 12.1'	November 19
2013	March 21	May 24	140" / 11.7'	December 18
2014	April 3	May 19	122" / 10.2'	December 1
2015	March 31	May 3	91" / 7.6'	November 8
2016	April 18	June 12	199" / 16.6'	October 30
2017	April 4	July 26	243" / 20.3'	November 10
2018	March 30	May 27	131" / 11'	November 20
2019	April 18	June 22	238" / 19.8'	November 29
2020	March 19	May 29	119" / 10'	November 13
2021	April 5		114.5" / 9.5'