The Empire State buildings base is almost 2 acres x 443.2 m tall and a square km is 247 acres. 2 * 443m * 37 million / 424 million (424,000 thousand) / 247 ~= 0.3m so covered to the depth of 1 foot. Which seems more reasonable.
ED: Ahh, they had wrong area for California. It's 424,000 square kilometers not "424,000 thousand square kilometers"
That 424million should be 424,000, so we are back at 300m deep. Except the ESB doesn't fill anywhere near all of the (2 acres x 443m) cuboid, so 100m is closer.
ED: Ahh, they had wrong area for California. It's 424,000 square kilometers not "424,000 thousand square kilometers"