Here's a close-up.
Mike

Has general aspect more or less like certain Thuja plicata cultivars such as 'Collyer's Gold'. Of the ones of this type 'Collyer's Gold' might be the most likely as a comparatively accessible example has been present in the Seattle arboretum for years, with rooted cuttings of it having been sold by the volunteers at the Calvert Greenhouse - in addition to others no doubt repeatedly helping themselves and putting it in local commerce.

The sprays and branching of yours is quite like 'Gelderland' but that is an assertively green form, with no yellowness - and less (or no) dwarfing of the growth.

This post was edited by bboy on Sat, Feb 1, 14 at 14:50

Thank you bboy. I always appreciate your knowledge and experience.
Over the years of doing new landscaping and yard makeovers I've acquired a modest variety of trees and shrubs, whatever caught my eye. If I saw something I liked I would ask for a few cuttings. More often than not, the homeowner didn't know the name of the plant. (You know) Precise nomenclature wasn't as important as it is now.
I've got another Thuja for ya later today. I'll take a picture when it gets light.
Mike..... Go HAWKS!

Figuring out which species it is (T. occidentalis or T. plicata) would be a good initial filter. If it is actually T. occidentalis then there are dozens of yellow cultivars. After doing that then trying the conifer forum here (if not done already) will be sure to produce discussion.