Vonn has served as TCSS Vice President for over 16 years. As Program Director, he has arranged more than 300 speaker and workshop programs for the society including monthly meetings, Sonoran conferences and a national convention. He is one of the founders of the TCSS cactus and succulent plant rescue program and Pima Prickly Park. He is an educational specialist on various species of Cylindropuntia, Grusonia and Opuntia and is one of the authors of the book, Field Guide To Cacti & Other Succulents of Arizona. Vonn created the TCSS logo and has been on the research committee for many years. He has also been recognized with various service awards as well as an honorary life membership in recognition of his numerous accomplishments.