Save the date!
In an effort to preserve the park and all it has to offer, Yellowstone National Park is offering the 'Inheritance Pass.'
In the form of a donation it will be used to maintain the park for the next 150 years. In the year 2172 is when the Inheritance Pass will be active for those generations to enjoy the park. People who purchase the pass will still receive an annual pass to be used while they are still alive.
Clever idea, and I believe the concept may draw people into the program. Unbeknownst to me, approximately 4 million people visit the park every year.