Hi Katie,
Thank you for your questions and photos, and especially for your patience in waiting for a response.  

Based on these two photos, the needle drop could be due to either disease or environmenat/abiotic damage.  Disease is uncommon here along the Front Range, but we always rule it out, since the environment is changing.  To differentiate between the two, let's collect some more info for starters.  If we can't figure it out via email, then you may need to bring in a sample.  Here are some questions to consider:

1. Confirming that the tree is a blue spruce.
2. When did you first notice the damage?
3. How quickly has the damage progressed?
4. Can you send additional photos to evaluate overall damage pattern on the tree?  Please include photos of the entire tree, photo of the lower few feet showing where the trunk emerges from the soil.
5. Where are you located?  If you're comfortable providing it, your address is helpful for looking at the tree over time on Google earth.
6. Do you apply supplemental water to the tree?  In winter?
7. I see water in the background - are roots in the water?
8. Are there other spruce trees nearby and do they show similar damage?

I look forward to your responses!

Best,
Mari Hackbarth