The Hosie family became mill managers/owners in the mid-19th century (Andrew Hosie as manager; later John Hosie Sr. bought the business). The enterprise expanded under the Hosies. John Hosie realised that coal-fuelled mills with steel rollers were effective new technology. He also wanted to use the SL&NCR rail line connecting Sligo with Collooney, Ballintogher, Dromahair, Manorhamilton, Glenfarne and Blacklion to Enniskillen andbeyond, which had commenced operating in 1887.  The Hosies completed a store in Dromahair in 1899, then between 1906–1910 they built a new coal-fired, steel-roller mill and warehouse beside the Sligo, Leitrim & Northern Counties Railway (SL&NCR) line about 1.5 km outside the village. This modernisation moved the centre of milling activity from the river/quay area to the railway corridor.

The mill (trading under names like Breiffni Mills / Hosie’s) milled flour and animal feeds for the surrounding farming community. During WWII and lean times the Hosies often accepted farm produce (eggs, poultry, vegetables) as partial payment — and kept local employment for decades. Milling activity declined and ceased in the early 1950s (railway itself closed in 1957).