<P> According to the U.S. Census Bureau, the county has a total area of 759 square miles (1,970 km), of which 751 square miles (1,950 km) is land and 8.7 square miles (23 km) (1.1%) is water . The topography consists of rolling hills and valleys and it is part of the region known as the Piedmont . </P> <P> Watersheds that serve Chester County include the Octoraro, the Brandywine, and Chester creeks, and the Schuylkill River . Many of the soils are fertile, rich loam as much as twenty - four inches thick; together with the temperate climate, this was long a major agricultural area . Because of its proximity to Philadelphia, Chester County has seen large waves of development over the past half - century due to suburbanization . Although development in Chester County has increased, agriculture is still a major part of the county's economy, and the number of horse farms is increasing in the county . Mushroom growing is a specialty in the southern portion of the county . </P> <P> Elevations (in feet): High point--1020 Welsh Mt., Honeybrook Twp . Other high points--960 Thomas Hill, Warwick Twp; 960 Barren Hill, West Caln Twp . Low point--66 Schuylkill River, Chester - Montgomery county line . Cities and boroughs: Coatesville 314; Downingtown 255; Kennett Square 300; Oxford 535; Parkesburg 542; Phoenixville 127; Spring City 114; West Chester 459 . </P> <P> Chester County has four distinct seasons and has a hot - summer humid continental climate (Dfa) except for some far southern lowlands which have a humid subtropical climate (Cfa). The hardiness zones are 6b and 7a . </P>

What is the highest point in chester county pa