[3] From 1974 to 1984 he lived and worked at Esalen Institute in Big Sur, California, teaching and studying with Grof, Joseph Campbell, Gregory Bateson, Huston Smith, Elizabeth Kübler-Ross, and James Hillman.

Tarnas is the founding director of the Philosophy, Cosmology, and Consciousness program at the California Institute of Integral Studies (CIIS), where he remains a core faculty member as of 2020[update].

It claims that the major events of Western cultural history correlate consistently and meaningfully with the observed angular positions of the planets.

[14] Tarnas featured in the 2006 film Entheogen: Awakening the Divine Within, a documentary about rediscovering an enchanted cosmos in the modern world.

[16] Advisory-board members include Christopher Bache, Jorge Ferrer, Stanislav Grof, Robert A. McDermott, Ralph Metzner, and Brian Swimme.

[17] In 2007 John Cleese and Tarnas gave some public lectures together at the Esalen Institute in Big Sur, California and in Santa Barbara.