my understanding is that SAGA is the humane society (deals with the aminals), and FOTHS is a fund-raising organization for SAGA, because SAGA does not have the time, staff nor resources to do fund-raising activities.
As a matter of fact there is a movement underway to formalize the arrangement and many of the Saga projects that have been on hold will be dusted off and revitalized.
You will be hearing more about this in the near future - but for now the people involved are still in the restructuring stages - please be patient - there is a lot of work involved - and of course it is all volunteer work. People have to fit it all in between work, families and other commitments.
From time to time when I have been down, I have stopped at SAGA to make a $ donation. They once gave me a cute Tshirt with dogs and cats and paw prints on it. Last month when I went by there, they were closed. If one wants to donate $ for animal care when they are in town, where to go?