It is with great sadness that we report that our friend and colleague, Bill Mitchell, passed away on May 27th, 2016. Bill served on the Sonoran Institute’s Board of Directors from 2010 to 2016, including 2 years as Board Chair. He was a passionate conservationist, avid outdoorsman and hunter, and strong advocate for engagement of underserved communities in the protection of our environment. Bill was generous with his time and contacts, always willing to make introductions and speak on behalf of the Sonoran Institute to partners, funders, and policy makers. His roots in activism extended way back, engaging on such diverse issues as the safety of nuclear weapons production to mining pollution. If Bill had had a personal motto, it would have been, “greater strength through diversity.” He was unstinting in bringing diverse elements of progressive movements to work together while also calling on mainstream environmental groups to confront their lack of racial and ethnic diversity. Most of all, he was a beloved member of the Sonoran Institute family, mentoring new staff and board members, quick with wise counsel or subtle wit. We will miss him dearly.