I grew up fishing that lake.  It does have some monster bass in both lakes.  The scenery is second to none also.  I haven't fished it in probably 5 years, but I noticed the last few times I had gone up there, the lake is over run with small fish.  Don't get me wrong, you will still get some quality fish, but not like in the late 80's, early 90's.  There is a ton of wood to fish in the canal that joins the two lakes, and lilly pads everywhere you look.  My favorite spot if you go up there is called split rock.  Just ask the people at the resort, they will know what your talking about.  Very fun lake to fish.

If you go east on HWY 174 from Grand Coulee towards Spokane, and then head north on HWY 21 towards Keller.  You will have to cross the river on the Keller Ferry (free).  Continue north through Keller and then turn left(east) on to the Inchelium road.  I believe it may be called Bridge Creek Rd.  I can't remember.  Anyway head towards Inchelium and you will find it.  I'm sorry for not knowing the milelage, but it has been a long time.  There are a couple different ways to get there, but this is the route I usually take.  It is a beautiful drive.  The north lake has a resort called Rainbow Beach and the south lake has a resort called Log Cabin.  Both are good bets.  I believe the Rainbow Beach resort has a better launch, although they both can launch a large boat without any problems.