The California Highway Patrol says Highway 41 is back open at the southern entrance to Yosemite National Park.
Both directions of the highway were closed for about two hours Thursday after crews said they noticed sulfur reacting with water along the roadway.
Sulfur was spilled in the area last Sunday after a big rig overturned. The highway was shut down shortly after and didn't reopen until late Monday night.
The driver of the big rig -- identified as KingDavid McClanahan Jr., of Los Angeles -- was arrested on suspicion of drunk driving.
Stay with KMPH News and KMPH.com as we continue to follow this story.