In a random browse through the online version of Bruce Elliott's Irish Migrants in the Canada's (see my article about this fantastic book), I came across a short reference to a migration of Irish people from north Tipperary to Rutland County, Vermont. Peter Patten, who is from that part of Vermont, is an expert on this migration and has researched it extensively.
He outlines that, "In the 1800s the Portroe Slate Quarries were one of the largest employers in North Tipperary. However, the onset of the Great Famine in the 1840s saw a significant decline in the numbers employed in Portroe. Many of those who lost their jobs decided to emigrate and...they pretty much reformed their community [in] Castleton, Vermont, in a strikingly similar landscape."
The density of numbers who made this Tipperary to Rutland County, VT migration is illustrated in this transcribed list of men who naturalized in Rutland County, VT from 1859 to 1873.