In article , David Brooks wrote:

If you follow I-90, watch for the sharp turn at Snoqualmie Pass (the main
pass over the Cascades). At least one plane has missed the turn and come to
grief in a nearby canyon.

There's a notch in the hill, a few hundred feet higher than the valley
floor. If conditions are not high enough to fly over the notch, you
shouldn't be flying in the mountains.

The other gotcha is coming west, when you start out VMC, fly around the
bend at Snoqualmie, and wind up in IMC on the other side. There can be
a discontinuity in the airmass right about there. Air following the
rising terrain condenses out the moisture, then as terrain starts to
descend again, the moisture turns back into vapor.


Morris