Big maps look really good. I remember the first time I used the 'hide panel' button in Google Maps, I literally voiced 'ohhh'. I'm not a fan of the modal dialogs on the linked site (nor the cufon - for whatever reason I can only see a handful of letters). The modal dialogs just add that unnecessary 'close' step which really detracts from casual browsing of trips.
On your site, you could definitely make the map bigger using a fluid design and you may be able to show all the cougars to some users. On an aside, the way you present the data on both the map and text is very slick.