- The O'Conor Don ancestral lands were in County Roscommon centred on Clonalis House near Castlerea. Alexander O'Conor Don died in 1820 without male heirs and the title was inherited by the O'Conors of Bellanagare. Some members of the O'Conor family of Bellanagare were distinguished antiquarians, see the ''Oxford Dictionary of National Biography''. In 1828 O'Conor Don of Belanagar was a member of the Grand Panel of county Roscommon. At the time of Griffith's Valuation, Charles Owen O'Conor was one of the principal lessors in the parishes of Kilcorkey and Kilkeevin, barony of Castlereagh. In the 1870s the O'Conor of Clonalis estate amounted to over 12,000 acres in county Roscommon with another 1000+ acres in county Sligo. At the same time Dennis O'Connor of Kingstown, county Dublin, brother of the O'Conor Don held 751 acres in county Roscommon and 287 in county Meath. In 1879 Charles Owen O'Conor offered for sale lands at Drimina, barony of Lyney, county Sligo. By March 1916 a final offer from the Congested Districts' Board for 1,368 acres belonging to Charles W. O'Conor, nephew of Charles Owen O'Conor Don had been accepted. A similar acreage (1,382) the estate of his mother Ellen I. O'Conor was vested in the Congested Districts' Board on 10 Feb 1916. The estate and family records are still held at Clonalis House. See www.clonalis.com for more information.
- The Nolan estate was in the parishes of Cloonfinlough, Kilcooley and Killukin, barony and county of Roscommon in the mid 1850s. In the 1870s Robert Nolan of Lisnaneane, Tulsk, owned 569 acres in the county. Gormley writes that Robert Nolan was the nephew of Catherine Lavinia O'Conor, widow of Dominick O'Conor Don [Burke's Irish Family Records states that he died unmarried in 1795] and eventually inherited Lisnaneane following her death. He records that the father of Robert Nolan of Lisnaneane was a Nolan from Queensfort, near Tuam. The Irish Land Commission eventually acquired the estate.