The Eastern Sierra and Inyo National Forest help Mammoth Lakes fill with activities and things to do. Camping, hiking and fishing are some of the most popular things to do. Information on everything including mountain bikes, golf, backpacking are available from our friends at City Concierge. Many sports and recreational activities listed are good all year round like going to Hot Creek for a soak, but it is always a good idea to check with a local official or Ranger to make sure the attraction is open.