Found on another site.
I spent a lot of my childhood and teen years on Catalina scuba diving and hiking the back country, but never hunted it.
You can hunt it, but there's a reason it's not hunted sufficiently to control numbers.
To make a long story short:
-The deer are small. -The island is essentially all private property that you can jump through some hoops to get access to. -The season is closed for the rut. -The archery season is in the middle of summer when the deer are nocturnal. -You have to take a boat from the armpit of Los Angeles to get there - it's an all-day affair between commuting to the harbor, to getting on the boat, to getting off the boat, and then getting home is another full day. -Hotels in Avalon are expensive. -The deer are no where near Avalon, for the most part. There are some roads, but there's no car rental and you can't just rent a golf cart and drive them. This is a back-country hunt. -Water is a big problem in the winter and a huge problem in the summer. -Above all else, the island is rugged and it's a shitty place to hunt.
Not many people are going to go through the hassle of going to Catalina to hunt elusive mule deer does and tiny bucks, so the population is high.
They could certainly make hunting there easier and more hunter-friendly, but most people aren't going to huff it miles on foot with a pack for this kind of hunt when they could have a better hunt for bigger deer elsewhere with easier logistics.