It is approximately 0.84 square kilometres (0.32 sq mi) in area and located in the historical barony of Moycarn in County Roscommon.
[2] As it is on the eastern bank of the River Suck, Tulrush is a part of County Roscommon.
Two River Suck fords (one at Pollboy and the other named "Riley's") were local crossing points.
These fords were used in 1691 during the Williamite War in Ireland by the army of the Jacobite general Marquis de St Ruth, moving from the Siege of Athlone to take part in the Battle of Aughrim, where he was defeated by the Williamite general Godert de Ginkell.
Ownership and control of the majority of the land in Tulrush rested with a landlord, the remnants of whose house are still visible overlooking the River Suck and facing towards Ballinasloe.