Vermont's great seal was designed by Ira Allen and accepted by the General Assembly in 1779. A new seal made in 1821 included much of the basic design of the original seal, but was not as symbolic in character. The current seal (adopted in 1937) is a precise reproduction of the original design.

The row of wooded hills indicate the Green Mountains; the sheaves and cow are symbols of agriculture; the wavy lines at the top and bottom represent the sky and water. The central focus of the seal is a pine tree (pine trees at that time were impressive, often standing a hundred feet above surrounding trees).

Source:

Vermont State Emblems: Vermont Secretary of State

Links:

State Seals - 50 States List
National Seal