"Grimm does not render the flower; he renders the force that drives it...The beauty of nature is not so much to be found in the individual stone or tree or stream, but in the dynamic and unceasing exchange of energy between them."
- Mikhail Horowitz. Woodstock Times

"(His extensive wilderness experience) provides him with voluptuous subject matter which he treats with a light, energetic touch.”
-Helen A. Harrison, New York Times

"His work comes from a biomorphic expressive abstraction which he carries into his own energetic and richly inventive mode." Sara Lynn Henry, Distinguished Professor of Art History, Emerita, Drew University

Within the natural world resides an abstract presence that, when intensely experienced, can later emerge in the work of certain artists. As an Abstract Expressionist painter, Calvin Grimm, marks his coordinates on canvases informed by years of exploration into pristine environments of intimate immensity. He was a wilderness sea kayaking expedition leader on the Alaskan and Yucatan coasts, and a backpack and horsepack leader in Wyoming for years, absorbing and contemplating what art historian and curator, Robert Rosenblum, reflects upon as "experiences of the spiritual...of the transcendental, mysterious...on a par with 'the great unknowables' of the universe". Donald Kuspit, "Sublime Fullness, Perennial Light, Eric Aho Paintings" 2011.

Grimm is widely recognized for his two murals at the San Francisco Giants AT&T Park in which he melds natural elements of the surrounding environment with symbols of architecture and baseball. Conversely, his "Ancient" series studies the 30,000 BC cave art of France and the spirits found in Native American horse masks.

His more recent series, "Deep Ocean/Deep Space" explores the similarities found in the vast aquatic and celestial frontiers, incorporating influences from Hubble imaging and abstractions of sea organism photographs with his personal experiences living from the fruits of the Caribbean while wilderness kayaking and snorkeling for five months at a time. He asks us, in this series, to surrender our need to know if we have entered a world of phosphorescing jellies or gaseous nebulae. Indeed, his paintings ask us to explore and engage in our own dialog with the inherent abstractions repeated throughout nature.