Overnight with awesome scenery?

I have a couple freinds coming out to visit 7/9 and 7/10 and we were hoping to go on a fun overnight backpacking trip easy driving distance from Portland (probably no more than three hours).  Lakes or creeks big enough to swim in would be a big plus.  And something not covered in snow would be good as well.  I was thinking the Shellrock/Middle Rock/Serene Lakes loop, but I was wondering if anyone had other suggestions.

Thanks!