Moles?

I was asked to inspect a yard for moles and did not find any mole hills or raised tunnels. It appeared to me to be a vole issue. However, along the driveway were a series of "spots." They were ~ 6-8 inches in diameter. The ground was soft under them. Any ideas? I will post a few yard pics. Thanks!

A couple more

During either the drier parts of the year (or in some cases, cold and semi-frozen), moles will go deep, as that is where their prey goes.
Consider in many places moles exist, up to 90% of their diet, year-round, are earthworms.
When the worms go deep, the moles go deep.
The mounds are their way of cleaning out the tunnels they are digging.
They dig side tunnels and push out the dirt to the surface.
When you see these mounds, the mole's tunnel could be, 6, 12 or even 18 inches deep or mole. You won't catch them with a trap designed to set in a run. . .not unless, you start digging !