The famous Californian resort now has the most snow in North America and is third in the world behind the Italian glacier Passo Tonale which has a 4.2m (14 foot) base but measures snow accumulated year round, and another Italian resort of Pejo.
Mammoth, with 307cm at the top of its slopes and 195cm at the base, is the most highly placed of five Californian ski areas in the world top 10 for snow depth. Each with 2.4 - 3m (8-10 feet) lying on upper slopes.
Mammoth has received 135cm (4.5 feet) of new snow in the past seven days and other Californian resorts have reported similar falls, the greatest 166cm (5.5 feet) at Sugarbowl.
Conditions are reported to be good across North America with healthy snowfalls in most areas including in the Rockies and New England. Even a resort in southerly Alabama opened this weekend.