I'm a Castaic Lake local and will be the first to admit that Castaic Lake fishing can be brutal. It's a tough lake to fish and most agree that it has more of a learning curve than a lot of places. Although it's a high pressure (heavily fished) lake, Castaic Lake Fishing remains some of the best bass fishing in the world.
Often those new to the lake or not well versed on its formation and behavior are quickly frustrated by the lack of fish. Rest assured, the fish are indeed in there including largemouth, smallmouth and striped bass, crappie, bluegill, catfish and trout on the upper lake.
If you're not completely new to fishing and want to see my current list of top baits and setups, check out this page: Castaic Lake Fishing Tips for Setups and Baits

Castaic Lake Fishing Locations
You can fish from shore, pier and boat (electric motors only) at the Castaic lagoon or from shore, dam or power boat at the upper lake.
Many who start from the pier soon realize the best way to find and catch fish is to walk the shoreline from the parking lot and boat ramp all the way to the far side end past the campgrounds. This is an excellent strip of shore for those who enjoy nature walks and like to sight fish.
Castaic Lake Fishing Tip - At various times of year, fish are shallow and wearing a pair of amber lens sunglasses will reveal fish you wouldn't see with the naked eye or with normal tint lenses. Buying a cheap pair will pay off on your Castaic fishing endeavors.
Boat vs Shore Fishing
Despite common belief, huge fish are caught from shore including largemouth bass and striped bass. If you have access to a boat or choose to rent a boat from the upper lake, your odds of catching fish at Castaic will increase dramatically.
The main difference is being able to maneuver a boat around structure and weeds so techniques and presentations can vary widely depending on where on the lake you're fishing at a given time of year.
Castaic Lake Fishing Tackle
One nice thing about Castaic is you don't need a ton of gear or fancy gear to catch fish. A starter spinning combo rod and reel with 6lb test and a few hooks, baits and weights is all you need.
Castaic Lake Fishing Presentations
Just about everything works, but generally Castaic, besides for those fishing for striped bass or monster largemouth's, Castaic lake tends to be more of a finesse lake and favor baits under 5" with smaller profiles and good movement.
This includes swimbaits, stick baits, jigs, finesse worms, ned worms and creature style baits rigged several different ways.
Seeing reports of numbers of fish caught on Carolina rigs and drop shots is common.
Live shad (if you can catch them) and live worms available at 7-11 or Gallion's near the lake are effective for catching a variety of fish species.
Castaic Lake Bait Colors
A variety of colors work well but generally natural colors matching the seasonal underwater buffet. Oxblood, green pumpkin, watermelon and varied shades of blue, pink and purple can be effective year-round based on weather, depth and water conditions.