Don't Go all the way to wilsonville for a hotel. if you head in towards portland on the 26, there are plenty of hotels from government camp to welches. Personally if you're going to a lake in the mountains you should be CAMPING. And there are plenty of sites to do so, both reserved and not. There are great hiking trails and it's also full of fish and crawdads. Boating is a must if possible.
Pleasant Hill can be spotted from Timothy Lake; what lovelier
way to enjoy a day than with a fine game of mini golf at Safari Sam's. You truly must fancy Timothy Lake. Going for a horse ride at nearby Continental Farms & Stables is always a fun thing to do.