Are you asking about fishing upstream or downstream from the dam? If downstream there is a bit of access but you should absolutely do some research to make sure you aren't going on private land. If you google around you should be able to find plenty of info on the lawsuits that have occurred over access.
If you are asking about upstream of the dam there is good acesss in hidden valley. Supposedly fish run out of the lake but I have never tried for them and am unsure as to whether they make it up as far as the public areas.