MacAdams was born in San Angelo, Texas and graduated from Princeton University in 1966. He is the author of a dozen books and tapes of poetry. As a journalist, MacAdams has been a contributing editor of theL.A. Weekly and has written regularly on culture and ecology for Rolling Stone, Men’s Journal, L.A. Times, and Los Angeles Magazine. As a political activist, MacAdams is a cofounder of Friends of the Los Angeles River (FoLAR) established in 1985 (and has served as Chair on their Board of Directors). FoLAR has been characterized by MacAdams as a "40 year art work" to bring the Los Angeles River back to life. In the years since, he has become the River’s most important and influential advocate. Among FoLAR’s many projects are an annual river clean-up, the "Gran Limpieza," which brings 2500 people down to the river to clean up every Spring; and an on-going series of conferences and planning workshops dealing with every aspect of the river.