Many conifer needles are used to make tea, usually due to their high level of Vitamin C. Western juniper (Juniperus occidentalis) is found in central and eastern Oregon, and those berries are edible. I use crushed juniper berries in my turkey brine every Thanksgiving. Another west coast juniper, the Sierra juniper (Juniperus australis), also has edible berries and needles, and is found south of the western juniper's range in California and Nevada.

Though I see no problem using the needles in a tea, I think they would be very woody and hard to eat, even in a smoothie! Spring would give you the most tender, new shoots, which might be preferable.

I would stay away from ornamentals as you don't know if or what they have been sprayed with.