She was intrigued by the idea of painting a canvas lying flat on the floor, and would later employ that technique for Mountains and Sea.

[7] In the summer of 1952, Frankenthaler went on a road trip to Cape Breton Island, Nova Scotia, during which she painted landscapes there using foldable easel equipment.

[8] The New York Times described Mountains and Sea as, "a light-struck, diaphanous evocation of hills, rocks and water," and the artist herself later said the canvas, "look[s] to many people like a large paint rag, casually accidental and incomplete.”[9] To create Mountains and Sea, Frankenthaler placed an unprimed canvas directly onto the floor and stained color directly onto it by diluting oil paint with turpentine and allowing the colors to bleed.

[9] Mountains and Sea is considered an important precursor to color field painting and has been described as, "the Rosetta stone of color-field.

[7] Morris Louis, an abstract expressionist painter and a contemporary of Frankenthaler, described the painting as, "a bridge between Pollock and what was possible.