"Sounds like what you have there is a vernal pool," he said.

Green frogs are found in the vernal pools and other water.

But a vernal pool is not just any blot of water.

On the way, we peered into vernal pools, which appear only in the spring.

Like vernal pools, they are only present at certain times of the year and generally have a circular shape.

It is estimated that only 3% of the area's original vernal pools remain.

Ponds that dry up completely each year are often known as vernal pools.

Vernal pools can form anywhere that a depression fills with water.

A certified vernal pool lies immediately to the west of the pond.

This protects the various species that live in the area's wetlands and vernal pools.