The land at the river's edge is alluvial floodplain, but Dauphin sits at the head of a narrow valley between two mountains, at the mouth of Stony Creek.
This section along the Susquehanna River is a gateway from the southeastern plains into the Appalachian Mountains and the north-central part of the state.
[5] Dauphin is surrounded by Middle Paxton Township, which comprises mountains and valleys south of the confluence of the Susquehanna and Juniata rivers.
The eastern ends of these valleys are generally undeveloped state game lands and protected watershed.
[11] Dauphin borough began as a settlement at the mouth of Stony Creek, the head of a valley between Second and Third Mountains.
[12] By the end of the eighteenth century, the Sturgeon property was owned by Revolutionary War soldier Timothy Green.
[13][14] Judge Green continued to add to his real estate holdings throughout the early nineteenth century.
The main geographic feature of this area are ancient hills or mountains and narrow valleys that generally run east to west with streams emptying into the Susquehanna River.
[14] Opportunities for economic expansion for the area appeared bright that year, as legislation was passed for creation of the Pennsylvania Canal.
Green acted on behalf of the Dauphin & Susquehanna (D & S) Coal Company, which had purchased eighteen tracts of land on or near Little Mountain, totaling about 7,000 acres (28 km2), from a group of businessmen.
[15] Charles Bird had earlier that year purchased four tracts of land in Middle Paxton Township from Judge Green.
In the early twentieth century, several "summer" houses were constructed on the edge of Second Mountain, south of Stony Creek.
Middle-class residents of Harrisburg built these houses as second homes to supplement their primary townhouses.
Development of the canal system of transporting goods during the early nineteenth century gave way to the rise of the railroads, which lasted for much of the twentieth.
In the last forty or so years, Dauphin Borough has been a bedroom community of Harrisburg, the Pennsylvania state capital.
Many of its civic centers had gone into steep decline, industry migrated elsewhere, taverns and hotels closed, as did schools and churches.
The railroad, which declined during the late twentieth century, has been reduced to two tracks paralleling the river, with no stops or stations in Dauphin.
Residents often had such a difficult time traveling across the borough that they waited until after morning and evening rush hours.
Most of these village centers have ceased to exist as the western part of Middle Paxton Township became suburbanized.
The remaining town, free of the traffic problems, became once again desirable as a location for commuters to Harrisburg.
Despite the losses in tax revenues owing to construction of the bypass, the local government continues to operate through cost-saving, cooperative efforts with Middle Paxton Township.