Timberline generally closes for a week or two at the end of summer due to typical maintenance. Other than that, they're open year round.
The problem, at this point is whether Timberline will be able to retain enough to snow this year to stay open that long. If you're going to be skiing at Timberline as well as staying on the mountain...try to do it as early in the summer as possible.
There are numerous places to stay. Hotels, cabins, houses, camping, etc. Things to do: fishing, hiking, drinking beer, checking out some of the shops and tents that will be set up in Government Camp. There's plenty to do on the mountain, it's just a matter of looking around. You'll keep yourself plenty busy.
Have fun
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