Both answers are correct. The Inn at Keystone is located about 500 yards from the Mountain House Base area of Keystone. It's a quick walk, 5-10 minutes, with ski gear. If you are interested in skiing out of the River Run base area, the Keystone shuttle can pick you up at the Inn and drop you off at the entrance to the River Run Village. Thanks and hope to see you over the winter!
Actually, I went their in april and you can ski in and out. We walked maybe 300m (5min with ski shoes on) at the back of the hotel to get to 2 lifts (Argentine and Peru express) that you can see from the hotel. Like that you can access all the slopes of the keystone resorts.
Hope that help!
Get an answer from Inn at Keystone staff and past guests.