Mr. Beckner,

Thanks for your very useful photos.

Here’s some information about needle browning: https://extension.usu.edu/forestry/trees-cities-towns/tree-care/pine-losing-needles

You asked about watering trees. Here’s how to test, in a very simple way, in paragraph #8: https://extension.colostate.edu/topic-areas/yard-garden/watering-a-home-landscape-during-drought-7-240-2/

Fall and winter watering is important. See this for more information: https://extension.colostate.edu/topic-areas/yard-garden/fall-and-winter-watering-7-211/
What’s your watering plan, especially during winter? See https://extension.colostate.edu/topic-areas/yard-garden/winter-drying-is-a-likely-cause-of-brown-pine-needles/I do not believe you failed to water your trees enough last winter. 

If you have additional questions or concerns, please contact Colorado State University Extension.

Sue, Weld County Colorado Master Gardener