Besides the land grants from the government there were several reasons folks did not move north and west of the Appalachians in Northern, PA until late in the 1700s and early 1800s. 1. Questions of clear land title. The northern part of PA was claimed by CT and NY as well as PA and it took the Continental Congress and the three states several years to work it out after the Revolution. Under the British few wanted to buy land from one proprietor group/syndicate and then find that they in fact did not own the land and either loose it or pay for it again to the ultimate winner of the dispute. [Main reason southwestern PA was settled first, was VA had a much clearer title and legitimately was able to sell land there from 1760s onward, though of course PA as a state's claim ultimately did win after the Revolution. [One does find NJ folks in Washington County, PA in 1780s & 90s]. But the Penn family land grant did not go that far west, so VA had a stronger claim for years to the Monongahela River Valley as well as the Ohio River. [You may recall that West Virginia was part of VA until during the Civil War.] There was actually a "war" fought in the early 1770s in the Wyoming Valley of Luzerne County between CT settlers and PA settlers. [CT got the Western Reserve lands in Ohio as a tradeoff for relinquishing their claims to northern PA in 1789 or so.] From our earliest days as a nation land/property ownership and claims have been one of the driving forces for the government. Much of the work of the Supreme Court for it's first 50 years was to be the ultimate arbitrator of land claims & disputes between & among states and address individual complaints about what share some folks did receive 2. Native Americans still lived in that region until after the American Revolution and they took sometimes violent exception to colonists moving into areas the British had given to them by treaty after the French and Indian war. This is one of the many reasons the various tribes in PA, NY and OH & Great Lakes region supported the British in the Revolution. England had said settlement for whites was to not go over the Allegheny Mountains or into the Ohio River Valley. They had reserved the area for the Indians, some of whom had been their allies in the F&I War and the rest they were trying to appease by treaties. In fact the British government had set up that whole trans-Appalachian area to be administered by their Canadian provenance government in the late 1760s to keep it out of the hands of the colonial activists, politicians and land syndicates from VA, PA, MD, NY & CT, all lusting for more territory. The British were trying to keep control and create the landed and class system they had in England in the colonies. Colonists were not buying it, that is one reason for the rebellion, to get a change in the land policies and make more available for all the growing population. Folks like Daniel Boone group to KY and others defied them and crossed the mountains. But before and through the Revolution they were a trickle, only a few hundreds who dared take the risk. Most of the PA Indians moved to Ohio & Indiana and Canada after the Revolution. During the period between 1883 and the end of the War of 1812 [in 1817 or so] the British in Canada encouraged the Indians to stage raids in the frontier regions and paid bounties at times for keeping settlers out of areas, so the frontier settlers really did live with threat and risk for two generations in the late 1700s, even after it was possible to legitimately go live on the northern PA land. 3. The mountains were a physical obstruction with little easy access or attraction to farmers. Mountains & hills, with no roads [the indian paths were on the top of the ridges, they seldom used the narrow valleys], totally covered by forest and woods and not much valley floor space with streams for cultivation anyway. Remember the Conastoga wagon is a creation of the future that came about partly to deal with this very movement of folks and goods into, over and through the mountains. Most folks still would use the river systems to move about as roads were poor at best when they existed. So NJ folks who moved on often went south to MD or VA then up river to Susquehanna, Shenandoah and Monongahela river valley areas in 1760s through 1790s. After the Articles of the Confederation finalized in 1787 and one knew which state owned the land, and folks had their "grants" for military service then they finally could go and move 50 -75 miles away to northern parts of PA and settle the Wyoming Valley and Luzerne County and points west in PA. If you ever drive on I80 across the northern part of PA you will see civilization and settlement never did take over all of this part of the world, still incredibly forested and undeveloped with low population compared to the rest of the East coast. Sort of our empty quarter, the preserve of PA hunters and now parks. The coal mining brought more people to parts of the region than anything else ever did. New Yorkers building the Erie Canal which drained later immigrants and settlers directly to the Midwest within the next 40 years, and had much to do with northern PA never becoming heavily populated and settled. Just a few of the factors that led to the delayed movement of folks from Sussex County and northern NJ over the Appalachians / Alleghenies / Poconos & into PA or southwestern NY for that matter.