<https://www.tetonsnowgeek.com/blog/2018/11/07/when-terrain-choices-are-the-answer?page&year=2018&monthnum=11&day=07&name=when-terrain-choices-are-the-answer/#breadcrumb>
<http://www.w3.org/1999/02/22-rdf-syntax-ns#type>
<https://www.tetonsnowgeek.com/blog/2018/11/07/when-terrain-choices-are-the-answer/>