Bit by bit Isaac headed West after his arrival in America. He followed a band of gold seekers to California in 1849 and was soon engaged in mining and later in stock raising. Of course he was hoping to strike it rich, but only got blistered hands for all his efforts, as described by Stella H. Day in her book "Builders of Early Millard". This of course was the time of the California Gold Rush 

Isaac was not registered in the California census for 1850 – the only Gandy in the records was John Gandy, gold miner age 24, born 1825 in England and living in Placerville and vicinity, El Dorado, California. I have not found details of Isaac anywhere else in 1850, but i guess he was moving around and still only 15 years old!

El Dorado, Placerville and Markleeville, California

Lake Tahoe and Carson City, Nevada

Read more about the life of a goldminer here, courtesy Jane at Old Mersey Times. "Diggins" California 1849.