Unless someone happened to have flown it in 1975, your best bet is the declassified CORONA imagery:
http://www.nro.gov/corona/facts.html You can get it from: http://edc.usgs.gov/products/satellite.html (scroll down to the CORONA section). This black and white photographic imagery spans 1960 to 1972, and is high enough resolution to make out individual trees. The neat part of this is that it was SPACEBORNE photographic imagery, which would drop the film canister from orbit and an intercept airplane would do a mid-air capture of the data. Very cool. Good luck! --j -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of Maya Kapoor Sent: Friday, March 23, 2007 10:39 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: looking for aerial photographs of Costa Rica Hello All, I am looking for aerial photographs of Costa Rica's Osa Peninsula. I need images from before Corcovado National Park was created in 1975 and some more recent images. Does anyone have any suggestions for possible sources? You can email me directly at [EMAIL PROTECTED] Thanks! Maya