Chris, Deer need three things food, water, and security cover. It looks like you have water, so that's excellent. How far do they have to go for feed other than the alfalfa? I've found the green fields don't do much for me after the first frost of the year, so usually they don't get used much during hunting season. In your area that might be different.
If you have mature timber I think one of the best things you can do is some timber harvesting. Deer will spend a majority of their time bedding, so I think it is important to be able to hunt near the bedding areas. Timber harvesting can create that for you.
I had some done on my property a couple of years ago and it's already starting to grow back extremely thick. The new growth that is coming up makes great food as well, and the deer seem to be loving it. I think the next few years will get even better.
If you do decide to have some timber cut do it in small patches. I marked off a number of different areas of one or two acres in size and had everything cut in those areas. Cut everything, including small trees, to completely open up the canopy and let sunlight in. You will be amazed at how quickly things regenerate.
In picking out the areas to be cut I put a lot of thought into exactly where to do it. Deer will tend to work around the edges of the cuts, and I tried to plan those so that I can take advantage of wind, etc. Remember, you're building a bedding area for them. Make sure you can take advantage of it when they start to use it.
Another big advantage of timber harvests is that it generated a lot more cash than I thought I might get, and that money could then be put back into other land improvements like more food plots, etc.