Both the method of "corner crossing" to access public land, and the use of a small ladder to get over a fence are common in the rural west.

First, there is important historic context: "checkerboard" land ownership, in which alternating PLSS squares are owned by private owners and the federal government, is very common in the west. It is a result of a subsidy/incentive scheme awarded to railroads, in which the railroad was given ownership of 50% of the land within a certain range (up to 40 miles) of the new railroad. This land ownership incentivized the railroad to develop both the route and services along with it, and because the federal government retained ownership of the other 50% it was assumed that the government would benefit from the resulting increase in property values. The way it has actually turned out is less than ideal; in many cases the federal government's squares are public land to this day while the railroad parcels have been sold to ranchers and other land-intensive operations. This results in a situation where vast acreages of public land are only accessible by corner-crossing at the intersections of this checkerboard.

Second, fences are put up mostly to keep cattle in, not people out. Where gate aren't installed, you could step over or through them, but with typical barbed wire construction that risks damaging the fence and pissing off a rancher. So on trails there are sometimes permanently fitted triangular ladders, and some people carry a ladder with them for this purpose.

The dispute over access to public lands that are near, behind, or otherwise restricted by private land is a long-simmering one in the west that is reaching a head. In many cases public roads pass through privately held ranches. It has long been common in some areas for ranchers to put up "no trespassing" signs on these roads, which must be ignored after confirming the road is public. There have been various incidents of landowners locking gates on public roads, but this isn't so common since it's pretty clearly illegal and usually you can get the sheriff to do something about it. The problem seems to have been getting acute though, and instances of people being run off of public roads and public land adjacent to private holdings seem to be increasing. At the same time, land owners are getting more strategic about acquiring land that fully encircles public parcels so that they can get exclusive access to them.

The root of this problem, as best I can tell, is the rise of the private game reserve. Many ranches have essentially been converted away from ranching operations (or at least they have been reduced to a secondary purpose) and now operate mainly as game reserves where people pay a good sum of money to hunt. This means that adjacent public lands are competition, both reducing the game inventory and providing alternative hunting destinations. So the owners of these game reserves have a great motivation to make public land around them inaccessible, and it's been difficult to organize against them since the BLM is not particularly interested in the problem.

There are definitely ways in which this is a selected case to test the issue, but the issue is not at all restricted to this case. Hunting organizations are looking for clear precedent that private land owners cannot restrict access to public land, land owners are looking for clear precedent that they can. Since this case has a very "clean" set of facts it's pretty attractive to both sides, as it'll be hard for a court to resolve without taking a stance on the broader issue of the legality of corner crossing.

In some areas there are fairly successful "open gate" programs that encourage ranchers to coordinate with state game authorities on providing access to public land that is in or behind their holdings. When the ranchers are mainly in the cattle business or farming, everyone can get along pretty well. There are disputes and there are ranchers that aggressively try to keep people out, but it's not so common. The big problem arises when the ranchers are primarily in the business of selling access to their land for hunting, in which case anyone hunting nearby who hasn't paid them becomes a problem in their eyes.