The painting presents a rustic mill, its architecture characteristic of the structures found in rural Canada during the mid-20th century. The building is coated with snow, reflecting the quietude of winter. The white of the snow is tinged with shades of blue, suggesting the reflection of the overcast winter sky, and the use of shadow indicates the depth and texture of the snowdrifts.

Bare trees frame the mill, their dark branches stark against the white and gray backdrop, providing a contrast that draws the eye to the central structure. The reflection of the mill and the surrounding landscape in the water adds a dimension of tranquility to the scene.

In the foreground, the presence of figures adds a human element to the otherwise still landscape. They are rendered in a way that blends them into the scene, suggesting a harmonious coexistence with the natural environment.

Roberts' use of impasto, where paint is laid on an area of the surface in very thick layers, gives the painting a tactile quality. This technique is particularly evident in the depiction of the snow and the mill’s walls, where the brushstrokes are visible, adding vibrancy and a sense of immediacy to the work.

Overall, "Mill in Winter (Bolton Mill), c 1960" is a testament to Roberts' ability to capture the essence of Canadian winters, evoking the chill in the air and the beauty of the season through his skillful use of color and texture.