Back country in Umatilla Mountains

I'm really new to this area and even newer to this forum, this being my first post. I am getting bogged down by job hunting and the economy and am in dire need of a break from urban-life. I am from the tri-cities area in Southern Washington and am looking for good backpacking trip in this part of the country. I did some research (what little online provides) and have looked over a few maps and decided that Umatilla/Blue Mountain ranges would be my best bet.

Does anyone have any experience in the backwoods of these? If so, could you give me hints to a few trails around here? I'm really looking for a one- or two-nighter, with not much more than 8-10 miles a day. I'm doing it with my younger (16 year old) brother who has no backcountry experience, so no extreme climbs, and no rope or fording, please.

Any help would be greatly appreciated.

P.S. I love how the spell check doesn't recognize the word "backcountry". Show's how far we are from usual social determinations.