Never seen one, but I know how important they are. I think they are the biggest bird in North America, and what I guess I would describe as the Apex Scavenger of the American West. Debates continue as to how far East and North they might have ventured,but from Oregon to Texas and all along California and down into Baja and perhaps even Sonora and beyond they soared.
They are huge, 9 foot wingspan. I have seen an Andean Condor, the biggest bird in the world with up to 10.5 ft wingspan, and all I could think to compare it to was a C-5 transport plane as it flew towards me, impossibly large... They are basically huge buzzards, the things look like something out of Spielberg's Dark Crystal, or like an animal caricature of the long lean faces of the old Indian groups from the same areas, like an old man from the Tarahumara in Mexico.
This tells the story better than I could. DDT was the problem, and they are susceptible to lead poisoning as well, which is a second major human cause of premature fatalities, since they often feast on carrion that has bullets or lead shotgun pellets embedded in it..They scooped up every remaining one in the wild they could about 25 years ago, the 20 or so remaining pairs, and started breeding. Their mating got all the attention of European Royalties for a while.
http://shadowofthecondor.com/facts.html
http://www.ventanaws.org/species_condors/
The Plan, with players like the USFWS, NPS; San Diego Zoo, Ventana Wildlife Society, and now the Mexican National Commission for Natural Protected Areas (CONANP) and SEMARNAT, the Mexican equivalent of an EPA, was to breed the remaining ones and try to increase numbers, then release them into the wild again as it became possible