Lettertrask mountain info maps weather Lettertrask is the 12122nd highest peak in the British Isles and the 1131st tallest in Ireland Also known as Leitir Treasc Elevation 279.0 m (915 ft) Prominence 150.0 m (492 ft) Category Marilyn Hill / mountain range North Mayo Nearest town OS map sheets OSi50: 023 (Mayo) OSi50: 031 (Mayo)