Editing St. Charles County, Missouri (section)

==Geography==
[[File:Boltonia decurrens millar.jpg|thumb|right|190px|St. Charles County is the only known habitat of the threatened decurrent false aster in Missouri.<ref>{{cite web|title=Decurrent False Aster|url=http://mdc.mo.gov/node/4803|website=Field Guide|publisher=Missouri Dept. of Conservation|access-date=September 2, 2015}}</ref>]]
According to the [[U.S. Census Bureau]], the county has a total area of {{convert|593|sqmi}}, of which {{convert|560|sqmi}} is land and {{convert|32|sqmi}} (5.4%) is water.<ref name="GR1">{{cite web|url=https://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_29.txt|publisher=United States Census Bureau|access-date=November 20, 2014|date=August 22, 2012|title=2010 Census Gazetteer Files|url-status=dead|archive-url=https://web.archive.org/web/20131021170230/http://www.census.gov/geo/maps-data/data/docs/gazetteer/counties_list_29.txt|archive-date=October 21, 2013}}</ref>

The highest elevation is {{convert|901|feet}} northwest of Augusta near Femme Osage Creek headwaters.<ref>USGS 1/3 Arc Second NED</ref>

===Adjacent counties===
*[[Lincoln County, Missouri|Lincoln County]] (northwest)
*[[Calhoun County, Illinois]] (north)
*[[Jersey County, Illinois]] (northeast)
*[[Madison County, Illinois]] (east)
*[[St. Louis County, Missouri|St. Louis County]] (southeast)
*[[Franklin County, Missouri|Franklin County]] (south)
*[[Warren County, Missouri|Warren County]] (west)

===Major highways===
*[[Image:I-64 (MO).svg|20px]] [[Interstate 64 in Missouri|I-64]]&nbsp;– Major freeway in the western portion of the county. Originally U.S. Route 40, the highway was upgraded to Interstate standards in the late 2000s. The highway was re-signed as Interstate 64 from the Daniel Boone Bridge to Interstate 70 in [[Wentzville, Missouri|Wentzville]] in 2009.
*[[Image:I-70 (MO).svg|20px]] [[Interstate 70 in Missouri|I-70]]&nbsp;– The major east–west thoroughfare in the county. It is mostly a six-lane freeway in the county, but there are sections in [[St. Charles, Missouri|St. Charles]] and [[St. Peters, Missouri|St. Peters]] where the Interstate widens to 11 lanes of traffic.
*[[File:Business Loop 70.svg|20px]] [[Business routes of Interstate 70|Interstate 70 Business]]
*[[Image:US 40.svg|20px]] [[U.S. Route 40 in Missouri|US-40]]
*[[Image:US 61.svg|20px]] [[U.S. Route 61 in Missouri|US-61]]
*[[Image:US 67.svg|20px]] [[U.S. Route 67 in Missouri|US-67]]
*[[Image:MO-79.svg|20px]] [[Missouri Route 79|Rte-79]]
*[[Image:MO-94.svg|20px]] [[Missouri Route 94|Rte-94]]
*[[Image:MO-364.svg|20px]] [[Missouri Route 364|Rte-364]]&nbsp;– A freeway in the southern and central portions of the county that begins at Interstate 270 in western [[St. Louis County, Missouri|St. Louis County]] and ends at Interstate 64 in [[Lake St. Louis, Missouri|Lake St. Louis]].
*[[Image:MO-370.svg|20px]] [[Missouri Route 370|Rte-370]]&nbsp;– A six-lane freeway that connects Interstate 70 in St. Charles County and Interstate 270 in St. Louis County.

===National protected area===
*[[Two Rivers National Wildlife Refuge]] (part)