I just spent almost two weeks hiking in Mount Rainier National Park. For lower altitude (3,000-5,000 feet), easy day hikes, I did okay, but struggled going up hills (to be expected, I guess...). Tried do an overnight hike (with 30 lb pack) that started just above 6,000 feet and couldn't get a mile before I had to call it quits or risk passing out and falling down the side of a cliff. Everyone's reaction will be different, but maybe less activity at higher altitudes will keep symptoms at bay? On another note, I'm also in Minnesota (Eagan). Hi, neighbor (for now)!