An excellent primer on gray whales:

Gray Whale: From Devilfish to Gentle Giants,” Whalewatcher, Journal of the American Cetacean Society, Fall 2013 Volume 42, Number 1, 72 pp

From the MMI Geospatial Ecology of Marine Megafauna Laboratory blog:
Introductions to themes discussed during the trip:
  • Save the Seal!” Robert L. Pitman and John W. Durban, Natural History magazine, November 2009, p. 48
  • How Now, Little Cow?” Robert L. Pitman and Lorenzo Rojas-Bracho, Natural History magazine, July/August 2007, pp. 28–32
And, for the ambitious:
  • The Log from the Sea of Cortez, John Steinbeck, 1951
  • The Marine Mammals of the North-Western Coast of North America: Described and Illustrated, Together With an Account of the American Whale-Fishery, Charles M. Scammon, 1874 (reprint)
  • National Geographic Field Guide to the Birds of North America, Jon L. Dunn & Jonathan Alderfer. (There is now a 7th Edition of this book.)
  • Baja California Plant Field Guide, Jon P. Rebman & Norman C. Roberts
  • Lagoon Time: A Guide to Gray Whales and the Natural History of San Ignacio Lagoon, Steven L. Swartz
  • E. Robustus: The Biology and Human History of Gray Whales, James Sumich