The waters of the River Ericht once drove a remarkable series of 14 spinning mills, the earliest, Muckle Mill, being built in 1798. Originally working with flax but later mostly changing to spin jute these enterprises brought employment and prosperity to the Blairgowrie and Rattray area through much of the 19th and early 20th century.

W. J. Watson suggests the name of the river takes its name from ScG eireachd, OG oireacht ‘assembly’, meaning a court of justice, perhaps on some eminence; Watson suggests the motte site at Rattray is meant here (Watson 1926, 439, 491). However, Oliver O’Grady, an archaeologist specialising in assembly mounds in Scotland, has suggested that the farm Courthill, north of New Rattray or the motehill in Blairgowrie, the site of which is just south-east of the old kirk, may be meant (O’Grady 2008, 134-50.