When the springtime hits Lassen Volcanic National Park, park officials begin the massive undertaking of trying to clear the snow off the park’s roads in order to open access to the summer destinations in the park.
The task, which began on March 3, typically lasts into late-May/early-June. Due to the lack of snowfall in the park this year, the job might be finished earlier rather than later. In 2018, with very little winter snowfall, the road fully opened on May 27.
Here is the 2021 snow clearing log from NPS:
March 23, 2021 – Clearing to Devastated Area was completed today. Thank you to CalTrans in assisting with steady snow removal and re-clearing the new snow that fell March 8th!
Road crew will transport equipment to the southwest entrance in preparation to begin clearing operations either Monday or Tuesday March 30 or 31. 8 feet of snow is on top of the road there and with steep slopes, avalanches, hairpins and heavy snow drifts, the clearing process is much slower than from the northwest entrance to Devastated Area. Stay tuned!
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.
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 highway may open in sections as conditions allow and as clearing operations continue. It will open to through traffic once it is safe for vehicles, not just only when it is cleared of snow. 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
The park highway encompasses 30 miles of stunning views through twisty hair pin corners, high elevations, and steep grades. The park highway traverses avalanche prone slopes with up to 2,000 foot drops and can hold a snowpack up to 40 feet deep.