The Kansas landscape was formed by alternating periods of deposition and erosion. The various herpetofaunal ecoregions are defined by their consilient properties to form general species range boundaries over time. Each herpetofaunal ecoregion is demarcated by its unique abiotic components of geology, soils, hydrology, and climate with the interactions of individual organismal physiology, natural history, life history, and evolution.
Most of Kansas's ecological communites have been greatly altered, and quite recently when measured against the timeframe in which these communities arose. One doesn't have to spend much time traveling across Kansas to realize the pronounced influence that humans have exerted upon the Kansas landscape. The greatest impact being the expansive conversion of diverse grasslands to the monoculture of cropland that extend to the quality and quantity of water in our streams and rivers. Only those few prairie landscapes that are impractical to convert due to topography/geology or were set aside as state or federal public lans have been conserved. Urbanization and deforestation have had significant regional impacts as well.

Political Boundaries — The Kansas-Nebraska Act of May 1854, created the Territory of Kansas, which extended from the western boundary of Missouri to the summit of the Rocky Mountains and from 37° to 40° latitude (excluding New Mexico territory in the southwest) on the south and north.
Kansas became a state following the ratification of the Wyandotte Constitution (the fourth attempt at creating such by the inhabitants of the Kansas Territory) by the US Congress and upon the signing by President James Buchanan of that bill into law on January 29, 1861.
The Wyandotte Constitution set the borders of Kansas as:

• East – Previously defined by the Missouri Constitution (10 August 1821) as the western edge of Missouri (the meridian line passing through the middle of the mouth of the Kansas River north and south), with the following adjustments. In 1836, the Platte Purchase added that area of land bounded by the 40th parallel, the previous western boundary of Missouri, and the course of the Missouri River to Missouri. Since 1935 the portion of the Missouri River above the Kansas River had been dammed, diked, and and leveed to the extent that its course became essentially static. In 1949 the Kansas-Missouri Compact set the current bounday along the Missouri River back to the center of the channel.
• South – The 37th parallel of north latitude.
• West — The 25th meridian of longitude west from Washington. A line of longitude at approximately 102.05° W of the Greenwich Prime Meridian.
• North – The 40th parallel of north latitude.

Kansas’ distinctive shape is a combination of both natural, altered natural, and arbitrary geographic boundaries as initially defined. Essentially, a projected geo—spherical rectangle, with a portion of the northeast cut off by the channel of the Missouri River, stretching from 37° N to 41° N latitude, and from ~94.607267° W to ~102.05° W longitude. While lines of latitude run in parallel circles that don't intersect, lines of longitude converge at the poles. This means that Kansas’s longitudinal borders are slightly further apart in the south. So if you'd look closely enough, the state resembles an isosceles trapezoid (omitting the NE border) rather than a rectangle. Consequently, the state's northern borderline is about 16 miles shorter than its southern one.
That's not where the story ends. There's boundary delimitation: the theoretical description of a border, as described above. But what's more relevant is boundary demarcation: surveying and marking out the border on the ground.
The first boundary survey (following the Kansas—Nebraska Act) began in 1857. The surveyors were tasked with demarcating Congress's delimitations into actual boundary markers. The official border would not be the delimited one, but the demarcated one. Unfortunately, 19th—century surveyors lacked satellites and other high—precision measurement tools. And considering the size of the task and the limitation of their tools — magnetic compasses and metal chains — they did an admirable job. They were tasked with staking straight lines, often through inhospitable terrain. So as you examine the demarcation in greater detail, you will find many errors and inconsistencies. In 1925, the Supreme Court ruled that the borders as surveyed were the correct ones. As demarcated, Kansas has an area of 82,278 mi².
Subsequently, Kansas was organized (and then often reorganized) into counties. Currently, there are 105 counties in Kansas.

Topology – Elevation in Kansas generally slopes downward from west to east. The highest point (4,041 ft above sea level) is Mount Sunflower near the Colorado border in Sherman County. The lowest point (679 ft) is where the Verdigris River leaves Montgomery County for Oklahoma. The western two—thirds of the state has a generally flat surface (undulating where eroded along principal river drainages), while the eastern third has many hills and forests.

Geology – Kansas is underlain by a sequence of horizontal to gently westward dipping sedimentary rocks. A sequence of Mississippian, Pennsylvanian, and Permian rocks outcrop in the eastern and southern part of the state. The state's western half has exposures of Cretaceous through Tertiary sediments, the latter derived from the erosion of the Rocky Mountains to the west soon after their creation ~90 million years ago. The state's northeastern corner was subjected to glaciation in the Pleistocene and is covered by glacial drift and loess.
The Ozark Plateau in extreme southeastern Kansas is comprised of rocks deposited during the Mississippian Period, ~350 million years ago. Landforms in the Ozark Border, Osage Plains, and the Cross Timbers are all Pennsylvanian in age, deposited ~300 million years ago. The Flint Hills of east-central Kansas and the Red Hills in south-central Kansas are both Permian, ~250 million years old.
Cretaceous—age rocks were deposited approximately 100 million years ago; while much of Kansas was a vast interior sea, form the landscape in the Smoky Hills and capping the norhtern Red Hills. The Western Plains and Cimarron Plains of western Kansas are composed of rock debris washed off the face of the Rocky Mountains over the past few million years. Much of this area is blanketed with wind deposited silt forming fertile (but dry) loess farmlands. The Arkansas River Sandsage Prairie and Arkansas River Sand Prairie are areas of recent deposition that border the Arkansas River.
Glaciers moved into Kansas several times for 750,000 to 10,000 years ago and scoured the northeastern corner of the state, leaving granitic rocks from far away and dense beds of loess soils.

Hydrology — Nearly 75 mi of the state's northeastern boundary is defined by the Missouri River. The sandy Kansas River, formed by the confluence of the Smoky Hill and Republican rivers at Junction City, joins the Missouri River at Kansas City, after a course of 170 mi through the northeastern part of the state.
The Arkansas River, rising in Colorado Rocky Mountains, flows with a bending course for nearly 500 mi across the western and southern parts of the state. With its tributaries, (Little Arkansas, Ninnescah, Walnut, Cow Creek, Cimarron, Verdigris, Spring, and the Neosho), it forms the southern drainage system of the state.
Kansas's other principal rivers are the Saline and Solomon Rivers, tributaries of the Smoky Hill River; the Big Blue, Delaware, and Wakarusa, which flow into the Kansas River; and the Marais des Cygnes, a tributary of the Missouri River.

Vegetation – The potential vegetation types exhibited in Kansas are largely determined by climate, hydrology, and soil characteristics. In general, as one goes west from the eastern edge of Kansas, the trees become more sparsely distributed (or confined to riparian areas) and the grass communities become shorter in stature.
Along the Missouri River border and within the Ozark Plateau (area bound by the Spring River in southeast Kansas) were predominant stands of oak-hickory forest.
Bordering those areas and following the Marias des Cygnes River (as far west as Allen, Anderson, Franklin, and Shawnee counties) and Kansas/Missouri rivers (as far west as Leavenworth, Atchison, and Brown counties) the forest opened up to a mosaic with mixed tallgrass prairie.
Beyond that, to the center of the state and including the Flint Hills, the area was largely mixed tallgrass prairie with floodplain forests. The notable exception is the oak-hickory Cross Timbers area, which persists in pockets from Chautauqua to Greenwood to Woodson to Labette counties.
The central portion of Kansas is a mixed-grass prairie and the western quarter is shortgrass prairie. Signification sections of sand and Sandsage prairie lie adjacent to the Arkansas and Cimarron rivers.
Agricultural and silvicultural actives have significantly altered the potential natural vegetation in Kansas. And urban sprawl from Johnson and Wyandotte counties to Shawnee County and much of eastern Sedgwick County has obfuscated those vegetative communities. Few stands of old-growth forest persist and most arable prairies have been converted to a monoculture of croplands (wheat, sorghum, soybeans, corn, and cotton predominately). Only the areas with significant topographical relief (Red Hills Prairie, Smoky Hills, etc), that are too rocky (Flint Hills), or have been set aside (Cimarron National Grassland) have been spared the plow.

Climate — Kansas's climate can be characterized in terms of three types according to the Köppen climate classification: it has a humid continental, semi-arid steppe, and humid subtropical. The eastern two—thirds of the state has a humid continental climate, with cool to cold winters and hot, often humid summers. Most of the precipitation falls during both the summer and the spring.
The western third of the state has a semiarid steppe climate. Summers are hot, often very hot, and generally less humid. Winters are highly variable between warm and very cold. The western region receives an average of about 16 inches of precipitation per year. Chinook winds in the winter can warm western Kansas into the 80 degrees Fahrenheit range.
The far south-central and southeastern portions of the state, have a humid subtropical climate with hot and humid summers, milder winters, and more precipitation than elsewhere in Kansas. Some features of all three climates can be found in most of the state, with droughts and variable weather between dry and humid not uncommon, and both warm and cold spells in the winter.
Temperatures in central Kansas reach 100 °F or above on most days of June, July, and August. These temps are often accompanied by high humidity and therefore dangerous heat indices. Temperatures are often higher in southwest Kansas, but it is less humid and the heat indices there are usually lower than the actual air temperature.
Although temperatures of 100 °F or higher are not as common in areas of eastern Kansas, higher humidity leads most summer days to heat indices between 107 °F and 114 °F. During the summer, nightly low temperatures in the northeastern part of the state, struggle to fall below 80 °F.
Precipitation ranges from about 47 inches annually in the state's southeast corner to about 16 inches in the southwest. Snowfall ranges from around 5 inches along the southern border, to 35 inches in the far northwest. Frost-free days range from more than 200 days in the south to 130 days in the northwest.
Kansas is prone to severe weather, especially in the spring and early summer. Despite the frequent sunshine throughout much of the state, due to its location at a climatic boundary prone to intrusions of multiple air masses, the state is vulnerable to strong and severe thunderstorms. Some of these storms become supercell thunderstorms; these can produce tornadoes, high straight-line winds, and large hail.
The highest recorded temperature recorded in Kansas is (121 °F) on July 24, 1936, near Alton in Osborne County, and the all-time low is −40 °F on February 13, 1905, near Lebanon in Smith County. Interestingly, Alton and Lebanon are approximately 50 miles (80 km) apart.

Herpetofaunal Ecoregions – At any given locality, the abiotic factors listed above interact with characteristics of the biotic elements occurring there. Collectively those localities where a particular species is present determine its geographic range. The Herpetological Ecoregions shown below were delimited by examining repeated range boundary patterns for the reptiles and amphibians in Kansas. And then characterizing those areas by their abiotic and biotic (primarily vegetation) characteristics. The ecoregions depicted below are used throughout the KHA distribution and habitat descriptions.