A Church of Scotland was built at North Ballachulish in 1829 at Creag Mhor, where the original churchyard still exists. The manse was built about a mile or so west in Onich (near the Onich Hotel). The minister also had under his charge the church at Ardgour, serving it on alternate Sundays. These churches were part of a government scheme involving about 43 churches and manses throughout the Highlands designed and constructed by eminent Scottish Civil Engineer Thomas Telford, who engineered the Caledonian Canal which was completed in 1822.
Before this, the area had come under the supervision of the parish of Kilmallie. The Disruption, as it came to be known, was the culmination of many years of disagreement over how much influence the State could have over the Church. Under a system known as Patronage, landowners could nominate ministers of their choosing to congregations, regardless of whether the congregation wanted them or not. This was considered by many, particularly evangelicals, as being totally unacceptable. They understood the historic position of the Presbyterian Church in Scotland to be that the Church and State were independent in their own spheres and they should not interfere in each other’s areas of authority, but rather help one another for the Christian good of Scotland. Finally, after all other options had been exhausted, almost all of the evangelical ministers in the Church of Scotland resigned their charges, and formed a new denomination: the Free Church of Scotland.
The first minister at the North Ballachulish church at Creag Mhor was John MacMillan, son of a Kilmallie farmer, who left the Church of Scotland in 1843 at the Disruption to join the newly created Free Church. The district served by the church then included both sides of Loch Leven and extended inland to Glencoe. A site for a church was given to the congregation, at Cuilcheanna in Onich which is now the grounds of Glenrigh House, with the building of the church and manse beginning in1845.
In 1900, the Free Church of Scotland joined with the United Presbyterian Church to become the United Free Church of Scotland, with a majority of members following suit. The current Nether Lochaber Parish Church of Scotland was built in 1911 to replace the Telford church of 1829 at Creagh Mhor, which had become unsafe. It was known as Onich Parish Church, becoming the Nether Lochaber Church in the 1950s. In 1933 a union with the former United Free Church at Cuilcheanna took place leading to the Cuilcheanna Church becoming redundant. As a result, it gradually became derelict thereafter.