Hello Aron,

Thank you for your question and photos, and especially for your patience in waiting for a reply.

The most likely cause of the upper tree death shown in the photos is Winter Dessication and/or Freeze damage.  

We have been seeing browning on conifers for over a year now: needle browning, needle drop and branch dieback. The damage is likely due to the combination of the sudden temperature plunge October 2019 (where the temps went from daytime 40's and 50's to single digits within a day or two), the sudden freeze over the Easter weekend April 10-13, 2020, and another sudden freeze in September 2020. In October 2019 and September 2020, plants hadn’t yet hardened off before winter, resulting in the scorch/burn symptoms, which were exacerbated with the April freeze event. In April, the tender young needles that had emerged sufficiently were frozen, resulting in small, sometimes brown and distorted leaves.  Buds that had not emerged yet were either delayed, or were killed by the freeze. Any needles or buds that were killed will not recover, but new growth will emerge and fill in the gaps over time.

To manage:

1. Based on what I can see in the photos, the buds on the dead portion of the tree appear to be brown and dry, indicating that they are not alive. Check them before deciding what to do with the tree (healthy buds will be plump and green if scratched, dead ones will be dry and brittle.)
2. If the buds are alive, then wait and watch for new candles to emerge (probably happening now.
3. If they are not alive then consider replacing the tree; with the upper 2/3 damaged, it will be difficult to prune the top off and train a new leader. Most nurseries will give a discount for replacement; you may need to bring in the tree for verification. 
4. To help protect trees against future sudden temperature drops in fall, and over the winter, hand water monthly when there has not been precipitation and temps are above 40F. In anticipation of a temperature drop, a good soaking to get moisture down 12+ inches will help the tree protect itself. Add 3-4 inches of mulch (pine needles or shredded bark, keeping mulch 2-4 inches away from the trunk) under the tree out to the drip line to moderate moisture and temperature changes around the roots.

References:

• CO State Forest Service https://csfs.colostate.edu/2020/04/26/ponderosa-pines-spruce-may-exhibit-winter-burn-damage/
• Winter Browning of Evergreens https://planttalk.colostate.edu/topics/weeds-cultural-problems/2114-winter-browning-evergreens/
• Environmental Disorders of Woody Plants (see drought and frost injury) https://extension.colostate.edu/docs/pubs/garden/02932.pdf
• Tree Planting Steps  https://cmg.extension.colostate.edu/Gardennotes/636.pdf
• Care of Recently Planted Trees (see watering guidelines in Table 1) https://cmg.extension.colostate.edu/Gardennotes/635.pdf
• Watering Mature Trees https://cmg.extension.colostate.edu/Gardennotes/657.pdf
• Fall and Winter Watering https://extension.colostate.edu/docs/pubs/garden/07211.pdf

Best regards,

Mari