Hi Thomas,

I'm sorry to hear about your tree!  Based on what I can see in the photo, I think you probably have pinyon tip moth.  The larvae, small caterpillars, feed just beneath the bark at the ends of the twigs.  They will likely be flying as adults now, laying eggs for the next year (there's one generation per year).  The larvae won't begin to tunnel into twigs until next spring.

At this time of year, you might even be able still to find some pupae inside the damaged twigs that would confirm the diagnosis.

These insects are not a threat to the life of the tree, but can be an aesthetic nuisance.  They are often controlled by natural enemies.  If you wish to apply insecticides, applying them in spring when the buds are beginning to elongate and the larvae are still on the surface would be most effective.  

For more information about life history, please see this fact sheet, which covers pine tip moths including pinyon tip moth: https://extension.colostate.edu/topic-areas/insects/pine-tip-moths-5-529/

I hope this is helpful.

Cordially,

John