Recently i went to a small pond in the rocky mountains and there was an abundance of small bluegill in the pond.  I contacted the HOA where the pond was located and they told me its never been stocked.  What are the chances that there are bass or any other species beside bluegill in the pond?

Fish it.... Throw a spinnerbait, chatterbait, or a ned rig... you will then know your answer. 

A Ned rig and a Rooster Tail should tell you pretty quickly.

Ask your local DNR, most states require ponds to have fish for mosquito control. 

Fish at dusk with a surface lure, if bass are there they will strike it or follow it.

Tom