Correction: The North American and Eurasian Plates are diverging at the Mid-Atlantic Ridge (a divergent boundary), where new oceanic crust forms as they move apart.
The Pacific Plate subducts beneath the North American Plate along the Cascadia Subduction Zone and the Aleutian Trench, forming the Cascade Range and Aleutian Islands—not the Rocky Mountains (which formed primarily from Laramide orogeny, far inland).
The Rocky Mountains are not a direct product of the North American–Eurasian plate interaction.