Most of these have been mentioned but with more details

1. Mammoth Lakes to Crowley. Take the roads down to the 395, down to the green church (riding on 395 is fine, very wide shoulders). Left at the church, then just follow that road all the way down and around the lake (the last two times I've ridden this we rode by Deena Kastor, Olympian marathoner, training up there). There is a decent climb up to the intersection of (i think) Owens Gorge road. We have turned there. You can go further, that's the route of the century mentioned above. This is mostly down going out then a nice climb going back. About 56 miles, map at http://trail.motionbased.com/trail/activity/2864120, profile is:





2. June Lake loop - haven't done it, but it's supposed to be pretty epic. I was advicsed by a local if I did it to avoid the back route out of town, lots of pressure cracks make the ride really tough. Same route as above, go left at the 395, think it's around 60 but lots of elevation

3. Mammoth to Reds Meadow - I've ridden from Mammoth Lakes to Minaret, but the backside was closed so I came back down. Passing the 9,000 foot elevation marker is breathtaking. Literally. As for the backside, it's not technically closed to traffic, as large shuttle buses use it, and people that camp back there can drive. It's a windy, one lane road at parts, not for the squeamish.

Town to Minaret Vista profile



4. Twin/Mary lakes - I missed it, but my friends rode up from town and around the lakes and said it was great.