Observation by MTRP Patrol Volunteers, George Varga, Marty Fink, Matt Franco. "The elapsed time between the first and last photo is 13 minutes. The rate at which this snake came out of the expanding burrow with mouth-fulls of dirt was amazing.
The snake literally was spitting a mouthful** of soil out. It kept going down and back up with mouth-fulls of dirt about every three, four seconds. When the pile got big
enough, it would use its body in a sinuous fashion to push the soil out of its way."
**In fact the snake retrieved "neckfuls" of dirt.
Short video of event: https://youtu.be/ZONMSUBvTeM