In reply to Lloydfletch:
For Cassin you want to wait a bit until the snowfield at the base clears somewhat. Coincidentally, today there will be heavy rain/snowfalls in the area.
Usually from mid-june onwards I'd say the Cassin will be in condition, although the area received little snow this winter, so it could be opening up a bit earlier this year.
For approach there are like a hundred topos available online. Generally: Bondo-> Laret (toll road unpaved) -> walk to hut-> walk to base. Walk takes 2-3 from parking at Laret. ~1000 m elevation gain.
Expect to be climbing in a queue in July. There are many other great routes in the area if you prefer some more solitude.
Post edited at 09:34