by Mark Cahill Living in Chicago, it was hard to notice that last weekend marked the changing of seasons. On Saturday March 20th, at 1:32pm ET, the sun crossed directly over the earth's equator: the Vernal Equinox. Soon the trees will be in bloom and we will all be trekking through our favorite weekend stomping grounds without any heavy parkas and long underwear.Stewart Udall was a true champion of the environment. He served as the Secretary of Interior under John F. Kennedy and Lyndon B. Johnson and was responsible for some the most important modern environmental victories of our time. Udall passed Saturday morning in his New Mexico home at the ripe old age of 90, just as spring was being born.Some of Udall's biggest accomplishments include the Clear Air, Water Quality and Clean Water Restoration Acts, The Wilderness Act of 1964, The Endangered Species Preservation Act of 1966 and The National Trail System Act of 1968. He also played a large role in the acquisition of Canyonlands NP, Redwoods NP, North Cascades NP and Guadalupe Mountains NP.Udall made every Spring a little more enjoyable for all of us, and for that, we thank him. More info here.