In Florence, your best bets are the Beachcomber Pub (20 taps, with some nice southern Willamette Valley picks) or Wakonda Brewing Co. I actually haven’t been to Wakonda yet, but the reviews are impressive.
Crater Lake isn’t ringed with pubs, so take some beer with you. Oh, and if you’re taking OR 58 from Eugene down to Crater Lake, you must stop in Oakridge at the Brewers Union Local 180. It’s a tiny brewpub run by one of the country’s leading advocates of cask ale. Ask for him if you want to spend an hour in lovely conversation. His name’s Ted and you can tell him I sent you.