Group items tagged

jQuery to parse the data

XPath to your YQL

relevant table from the Wikipedia document

SELECT * FROM html WHERE url="http://en.wikipedia.org/wiki/List_of_United_States_National_Parks_by_state" AND xpath="//table[@class='wikitable sortable']"

XML or JSON

creating an XML document

AJAX call from jQuery and then loop over the JSON

documentation could maybe be clearer

CSS style selection engine as well as the XPath one