MINERAL, CA – The 30-mile highway through Lassen Volcanic National Park will open to through traffic on Friday, June 3. A lower-than-average snowpack accelerated snow clearing operations. Intermittent closures along the highway are possible due to repair work, as well as inclement weather. Please check the weather forecast before traveling to the park. In other areas of the park, the road to Butte Lake is open; Warner Valley and Juniper Lake roads remain closed at the park boundary due to post Dixie Fire hazards.
https://www.nps.gov/lavo/learn/news/lassen-national-park-highway-open-to-vehicles.htm