At their marriages, Bridget and Mary Callahan gave Tirargus as their Townland, which is quite near Legnahoory. Their parents had died (James in 1873 and Mary Doherty possibly 1878) and they went to live with grandparents after 1873. There is a death record for a Mary Callahan, age 27, in Tirargus in 1878, with Michael Doherty as informant.
A Michael Doherty died in Tirargus at the age of 91 in 1896. A Hannah Doherty, wife of Michael Doherty, a farmer, died at 65 in 1889, with son Mick Doherty as informant. (Tho that age would mean she could not be Patrick's mother as he was born in 1832... still: ages are often wrong on such documents.)
In the 1901 census a Michael Doherty and wife Catherine McGinty live in Tirargus and with them is their "nephew" Henry Callaghan. Mary Callahan Callaghan's eldest son was Henry, same age. Michael and Catherine were married in 1895.
I think there is not a Michael Doherty in Tirargus in the Griffith's, but there are other Dohertys there.
My aunt visited children and grandchildren of Mary Callahan Callaghan in Letterkenny in the late 1980s and was told the family (Callahans? Dohertys?) came from "up near Church Hill." In Patrick Doherty's Australian obit, it said he was born in Church Hill. Maybe the Dohertys moved from Church Hill to Tirargus? I do have proof through correspondence that Patrick Doherty's children were cousins to Mary Callahan Callaghan.
Thanks, Julie. I know it's a long shot as there are so many Dohertys in Donegal.
--Meg