Conservation Biology, ENVS 120 (Zavaleta), is studying the tiny Mexican island of Guadalupe. Often it is shown as an inset on maps of the region (Northern Baja California). G4481.E63 2001 .B3 , Title: "Baja California north (Pacific Side)", is the best map we have. This island doesn't appear to be covered in our set of topo maps, 1:50k. There is a map online at
http://www.sdnhm.org/research/guadalupe/map-guadalupe.html
We have ordered a map from NOAA (21661), should arrive 10/18.
We have a 19th century C&GS map of the island (not in Cruzcat; G4477.G8 D4 1892 U5) that is interesting.
See http://www.gygis.com/guadalupe-island.html for great photos & description.
There is a UCSC dissertation on the Guadalupe fur seal, QL 737.P63 G35 1994, which includes maps.