The particular type of cabin relevant to National Forest Homeowners is a cabin located in USDA Forest Service land. It is allowed to exist by a special use permit. Currently, those permits are issued for no more than 20 years at a time.
These are not leases; they are permits, with fewer rights than a lease. They are not 99 year leases, but are limited in term. The owner of a cabin only owns the cabin, which is personal property, and only has the rights to the underlying land that the permit allows. Most cabins are located on a "lot" designated by the Forest Service, but the rule is that the general public cannot be precluded from the use of the lot, so sometimes the use is stated as limited to the footprint of the cabin.
There are many consequences arising out of this type of asset, and many of those are discussed in the other drop down bars in this section.