In a word, yes.
By using your browser's options to delete the files, the files themselves are not actually deleted - just the link that makes them easy to view.
If you took my Yellow Pages from me, it wouldn't stop the phone number for my local plumber existing, I just wouldn't be able to find it.
They're still on the hard drive but your PC will know that if it needs the space it can overwrite them - if you don't use the hard drive space, they'll stay there.
I don't actually know how to access them but they are there unless you use a program to clean your internet tracks - these progs go to the trouble to overwriting these files with empty space to erase them completely.
On a cheery note - this is how people with child porn (like Gary Glitter) get arrested : they delete the files and assume that they're gone forever and then someone in a PC repair shop finds the files.