It is important to be aware that Colorado is experiencing a resurgence of mountain pine beetle (Dendroctonus ponderosae) activity. Beetle populations generally increase significantly following warm, dry winters—like this year.

Mountain pine beetle populations are expected to explode this year. Beetle infestations are predicted to be most severe in highly visible ponderosa pine forests along the Front Range.

Some key points to keep in mind about this insect:
Mountain pine beetle is a NATIVE insect. It is endemic to CO and is not invasive.
Individual beetles are small, the size of a large grain of rice. They damage/kill trees through mass attack.
Beetles will generally only infest pine trees. Attacks on other conifer species can happen but are rare and often not successful.
Beetles prefers ponderosa and lodgepole pine but will go after other pines when beetle populations increase and when preferred species are not available.
Beetle populations have boom and bust cycles. We are currently at the start of the next boom cycle.
Beetles prefer larger diameter trees (generally larger than 10inches in diameter). Landowners/managers with high-value, large-diameter pines may consider contacting an arborist for preventative methods. Trees can be chemically treated when adult beetles are flying, but this is not cost-effective for many landowners.
Beetle trapping is effective for monitoring populations. It is NOT used for control.
There is NOT a practical way to treat trees already infested with beetles. However, cutting and disposing of heavily infested trees, before new beetles emerge, can reduce attacks on surrounding trees.
The risk of extreme fire is higher the year following heavy beetle infestation (red needles) and the year after that (gray needles), but risk declines as those fine fuels fall to the ground.

CSFS has a great mountain pine beetle page that is updated regularly:
https://csfs.colostate.edu/forest-management/common-forest-insects-diseases/mountain-pine-beetle/