Batt quickly proved to be useful in the "Inland trade"' aspect of the company business and was influential amongst the Indians near present day The Pas, Manitoba.
In August 1773 he and James Batt left York Factory, Manitoba but had to turn back because of low water.
In 1776, he hired his services to Joseph Frobisher, one of the "Pedlars" who carried on trade competitive to the HBC.
Although illiterate, and therefore unsuited to keeping proper records and making written reports, he won the trust of the natives and married into their society.
"Isaac's House", a temporary post somewhere downstream from Prince Albert, Saskatchewan was named after him.