I found this type of insect in two instances ‘digging’ (a nest?) in the stonedust of my pathways. (Eastern Ontario)
This is the great golden digger wasp.
As you suspected this wasp is digging a nest. The female digs a burrow almost vertically. Cells are dug radiating out from central tunnel. Larvae are fed crickets, camel crickets, and katydids. The wasp stings the prey which paralyzes it not killing it as the larva like live food. One paralyzed prey is placed in each cell, and one egg is laid on it.
There is one generation per year. They are found in fields or meadows with sandy areas nearby, so it liked your sandy path. These are beneficial and do not sting unless really hasseled.
The wasp will feed on nectar of flowers.