I too spent my youth on those hills and canyons, but that was 15yrs ago. There used to be many and even some big deer....lots of muledeer/blacktail crosses.
I can remember not being able to leave camp without seeing deer , especially during elk season back when that season was in November. Now in those same areas I know like the back of my hand, it's rare to see a doe. WDFW's estimates of the yakima units' deer herd show a decline of over 50%.
Wish I had a better story for ya, but none of my good Bethel Ridge stories go past 1995 in that unit.