The other street you list - not familiar, but probably the same situation - there are alot of new construction homes recently foreclosed and just getting on the market.
Michael is absolutely correct..... after checking both listing services there is only one active listing inn the indian hills neighborhood. If you are seeing more signs, these are homes that have either expired(come off the market) whose realtors have nor taken down their signage, for sale by owners or possibly a for sale by owner service company who is working with the owners.
If I can be of any further help email me or call me at your earliest convenience.
Chuck Green, Realtor
Keller Williams Realty