Spruce trees branches drying and dropping.
It looks like you could have a couple of things going on. How much water are your trees receiving? Trees need a substantial amount of water throughout the year, including in winter. Below are some fact sheets with recommendations on watering your trees throughout the year.
The second photo looks like the older growth is turning brown, but the tips are still green? If that is the case, the tree may be shedding its older needles in response to stress, potentially from not enough water.
I noticed there are some wood beams/posts under the tree. Are they buried deep into the soil? If so, that could potentially affect the root system. Are they old railroad ties? If so, it is possible the railroad ties could be leaching some wood preservative chemicals into the soil.
Also, the new growth branches you are noticing on the ground are consistent with squirrel damage. Squirrels will sometimes clip the new growth branches off the tree.
Here is a fact sheet on fall and winter watering trees: http://extension.colostate.edu/docs/pubs/garden/07211.pdf
Here is a fact sheet on watering trees during a drought: http://extension.colostate.edu/docs/pubs/garden/07240.pdf
Here is a fact sheet on keeping tree roots healthy: http://extension.colostate.edu/docs/pubs/garden/02926.pdf