They don't lay them underground - not very deep anyway. They make nests and lay them under objects.

I've never found a wild a clutch, but it isn't too uncommon to find them under objects (like logs and rocks).
-----
6.8 L. getula californiae - 11 eggs (Cal. King)
1.2 L. getula nigrita (MBK)
1.0 L. getula floridana (Brooksi)
1.0 Pantherophis guttatus guttatus (Corn)
0.1 Pituophis catenifer catenifer (Pacific gopher)
3.3 Elgaria multicarinata multicarinata - 14 eggs (Cal. Alligator Lizard)