The Sierra is great for rock climbing (get on the Hulk) but the ice routes aren't worth traveling for and there aren't any mixed routes worth the name.
For ice and mixed you want to be in Canada much earlier in the season or much later.
You're also kind of late for mixed and ice in the Alps as well. Ditto the Ruth.
What about the Kahiltna? There's the Cassin or the Moonflower on Hunter, both of which were in good shape in early June this year, not so much by the end of the month. Lot's of other objectives around the glacier as well if you don't mind crowds.
Check out the Taco: