The population of Lehigh Township was 9,728 at the 2000 census.
Lehigh Township was named after the Lehigh River, which sweeps its eastern border.
Warrior's Path, a war trail used by the Indians traveling from the Susquehanna River toward the Delaware River, is located near the top of Onoko Falls. Later, while timbering during the early boat building era of the Lehigh Canal, lumbermen referred to this place as "Raftsman Path".
The character of the land was indeed mountainous and therefore very little was tillable. Villages were Laurytown, Penn Haven, and Rockport. In the 1870's, Glen Onoko was developed by the Lehigh Valley Railroad and it became a major tourist attraction.
Lehigh Township was created in 1875 from a part of Lausanne Township. It is bounded on the northeast by the Luzerne County line, on the northwest by Lausanne Township, on the west by Packer Township, on the south and east by the Lehigh River which separates it from Kidder and Penn Forest townships.
In 1880, the population of Lehigh Township was 36. Its tax assessment was $26,292 with real estate of $23,742 and personal property of $2,550.
In 1883, the assessment roll of Lehigh Township revealed 198 taxable inhabitants. Farmers included Charles Carroll, Patrick Cormor, Anthony Cull, Anthony Felder, John Graaf, Michael Halley, Conrad Hinser, Hiram Hinser, Jacob Hellinger, Frank Kingle, Adolf Ludman, William McDonnell, Edward McGill, Michael Meyers, David Miller, Gabriel Miller, Jacob Petry, Christian Ramsey, John Shaffer, Samuel Simon, George Stetler, William H. Taylor, John Torny, John Wallace, end Isaac West.
In the same assessment, the Lehigh Valley Railroad owned 243 acres on the Porter House tract, 197 acres at Balliet's, 370 acres at James Moore, 187 acres at Penn Haven Junction, and a house each at Turn Hole, Bannin's, and Booth's.
The Central Railroad Company of New Jersey was assessed on a house each at Turn Hole, Penn Haven, Oxbow and North Penn Haven.
Quakake Creek (1) enters the township from the west and joins Hazle Creek (2) at Black Creek Junction where it continues east before emptying into the Lehigh River (3) at Penn Haven. Laurel Run (4) enters the township from the northwest and flows southeast to join Indian Run (5) enroute to the Lehigh River below Rockport at a point that whimsically should be dubbed as "Die Lorelei of Pennsylvania." (In Germany, Die Lorelei is located between Koblenz and Frankfurt at a sharp bend along the mighty Rhine River). Leslie's Run (6) rises near the Luzerne County line and flows into the Lehigh River in the northern part of the township. Broad Mountain (7) constitutes the southern portion of the township, while Quakake Valley(8) passes between it and Bald Ridge Mountain (9). Bald Ridge Mountain reaches across the township from east to west, and Laurytown Valley (10) is situated on the north side of this mountain.
As of the census of 2000, there were 9,728 people, 3,680 households, and 2,833 families residing in the township. The population density was 126.5/km² (327.7/mi²). There were 3,816 housing units at an average density of 49.6/km² (128.6/mi²). The racial makeup of the township was 98.67% White, 0.36% African American, 0.20% Native American, 0.17% Asian, 0.16% from other races, and 0.43% from two or more races. Hispanic or Latino of any race were 0.74% of the population.
There were 3,680 households out of which 31.7% had children under the age of 18 living with them, 67.0% were married couples living together, 6.9% had a female householder with no husband present, and 23.0% were non-families. 18.0% of all households were made up of individuals and 8.2% had someone living alone who was 65 years of age or older. The average household size was 2.62 and the average family size was 2.98.
In the township the population was spread out with 22.5% under the age of 18, 6.3% from 18 to 24, 29.5% from 25 to 44, 27.9% from 45 to 64, and 13.7% who were 65 years of age or older. The median age was 41 years. For every 100 females there were 102.9 males. For every 100 females age 18 and over, there were 98.6 males.
The median income for a household in the township was $48,263, and the median income for a family was $55,216. Males had a median income of $37,307 versus $27,206 for females. The per capita income for the township was $21,400. About 2.3% of families and 2.9% of the population were below the poverty line, including 3.1% of those under age 18 and 4.1% of those age 65 or over.
The Township is served by the Northampton Area School District.