For those who really want to geek into this topic . . . (god I really wanted to type , , , for
@wllm1313's sake, but it irritates me too)
Roman Law stated, "cujus est solum ejus est usque and coelum" (a land owner controls from heaven to hell). English law picked this up by the time of Henry I, but those in the know at the time called it "Lord Coke's ad coelum doctrine", see, Blackstone circa 1766. This approach rendered lawful corner crossing a physically impossible task.
The US adopted this principle generally as it incorporated English common law as a basis of our own - so, in 1776 corner crossing in the 13 states was effectively trespass. Various states took twists and turns along the way, but was a minor area of interest until air travel pushed the point.
In 1946 a federal "takings" case, SCOTUS (US v Causby) proclaimed that all "airspace above the minimum safe altitudes of flight prescribed by the Civil Aeronautics Authority" is public domain. In that case, I think the elevation in question was 83ft - but they declined to prescribe a specific boundary and subsequent cases seemed to gravitate to 500ft. Various states began using the Causby case reasoning to reign in vertical rights more generally, but not all.
As it relates to "stepping over" a corner - it remains gray in most places, but if a client asked me this question I would suggest that until you can point to a specific statute or precedential case in your state of interest then you must assume that corner crossing by foot (or pole vault) will start with a presumption that it is trespass.
Where such clear case law or legislation doesn't exist, the path to resolution is either directed litigation in the hopes a state court goes the way of SCOTUS in 1946 and just throws the old out the window, or specific legislation to reverse traditional common law.
But this is just the formal restatement of the law - whether someone chooses to follow it or not, finds the risk too great or di minimus, relies on local culture and relationships, or local/state officials actions/inactions/statements, etc will cause each hunter to reach his/her own conclusion of what to do.
As an aside, Causby is a good reminder of how "it's always been that way" arguments can rest on quick sand. For over a thousand years and across multiple countries, incl. in the US since its founding, the law was clear - from heaven to hell. But in one case in 1946 SCOTUS declared this centuries-old precedent "[had] no place in the modern world". And that was that. At least as it related to airspace needed for air travel.