It would be helpful to see a good quality close-up of the needles, and one of the whole tree.  Many insect and disease problems are specific to the kind of tree.

This sounds like it could be a spruce.  Take a look at the information and photos in this link to see if you can find similarities:
http://www.extension.umn.edu/garden/diagnose/plant/evergreen/

Here are a few pictures I took, hope this tells you more. Do pine needles ever grow back or will that area always stay bare like it is now? Thanks, Phyllis

Hi Phyllis,

Needles will not grow back.  If there is no sign of new growth, these branches are dead and Can?, May?, Should? be removed.  If these trees are infected with a "curable" disease or infestation, they may recover, but it will take considerable work to train a new leader branch that will encourage the trees to grow Upwards - not Outwards.

It's really hard to diagnose your trees with just a few photos.  This could be the result of insect damage, or fungal damage, or even herbicide damage.

Before I send any information about pruning and training new leaders, I think you need to get these trees assessed by a certified arborist who can come on site, look closely at these plants for insect damage, fungal growths and other disease issues, and make some recommendations.

Here is a link that should help you find a certified arborist:
http://www.myminnesotawoods.umn.edu/2009/01/finding-tree-care-help-certified-arborists-and-mn-tree-c...