Current info--not much help to our OP who already has tickets to LAX, but might help others:

So far (no guarantees!) the Cascade Range in Oregon between Willamette Pass and Mt. Hood is OK. That includes several spectacular wilderness areas like the Three Sisters and Mt. Jefferson. Portland would be the obvious flight destination. It's hazy up here from Southern OR and CA smoke, but no problems at ground level. The NWS forecasts a marine push this weekend, so that may go away.

As far as I can find out, the Wallowa Mts. in NE Oregon are fine. They are granite mountains like the Rockies. Unfortunately they are a long way from anywhere--like an 8 hour drive from Portland.

The Washington Cascades have seen a lot of fire starts the past 2 weeks due to dry lightning storms. For some reason, Oregon has lucked out so far, except in the southern part of the state.

Of course fires could start literally any minute in any of these currently smoke-free locations!

I sure hope our OP, Rick, and our other frustrated hikers find something!