A Maine native, Merriam began carving at the age of 12, and worked in the family business carving log benches. He graduated from the New England Conservatory of Music as a Piano Technician, and began working as a piano repairman and tuner. Carving in his spare time, Merriam began created commissioned carvings. Merriam turned to carve full-time in 1982, when he went to work for a sign company in North Conway, and won six national awards for Dimensional Sign Design.
A self-taught water colorist, Merriam went on to study under George Carpenter. Carpenter was the last surviving member of the Whiskey Water Color Association, and he passed many of his techniques on to Merriam. Often beginning his work plein air (working outside, painting what is seen in that moment), Merriam begins by painting small, quick studies of his subject matter. In these studies he captures those variables that swiftly change in the outdoors: the wind, light, and movement of a scene. He then returns to his studio in Portsmouth, New Hampshire, to complete a larger final piece based off of the study.
Along with painting and carving, Merriam is an accomplished poet, storyteller, and musician. Merriam has published several children’s books that he wrote and illustrated himself.