National Park Service: verschil tussen versies

!rowspan="2"| Naam<ref>{{citeen}} web|url=[http://www.cr.nps.gov/history/hisnps/NPSHistory/directors.htm|title= "Directors of the National Park Service|publisher="], National Park Service|accessdate=2008, online geraadpleegd op 19-04-05}}2012.</ref>

! width=30% | '''Onderverdeling'''<ref>{{en}} ''The National Parks: Index 2009–2011,. Official Index of the National Park Service'', Government Printing Office, Washington D.C.;, 01/03/-01-2009.</ref>

! width=10% | '''Bezoekers'''<ref>{{citeen}} web|url=[http://www.nature.nps.gov/stats/viewReport.cfm |title=NPS"Annual StatsSummary Report for: 20092011"], |publisher=Nature.nps.govNational |date=Park Service, online geraadpleegd op |accessdate=2010-10-03}}-2010.</ref>