Very shortly, probably today or tomorrow, you are going to read one of many articles that say that $119 million dollars of Trump's charitable deductions were in the form of conservation easements on a 230 acre woodland estate in Bedford, NY called "Seven Springs". The tenor of many of these articles will be designed to enrage you, and to inspire you pick up your pitch-forks and torches and call for an end to this egregious example of "socialism for millionaires".
I urge you to lower the pitchforks, dim the torches, and gain some understanding before you go pillaging and burning.
A conservation easement is an arrangement wherein wild lands and wildlife habitat are preserved for wildlife, often in perpetuity. One of several typical arrangements (and the one I believe was used for the "Seven Springs" land) is the property owner retains the right to use the land for limited personal usage, and signs a covenant surrendering development rights to the bulk of the land. In exchange for this "covenant to let the land remain wild", the property owner is given a tax deduction equal to some percentage of the free-market value of the land over some period of years. This arrangement has resulted in something on the order of 56 million acres of land being preserved in the United States, without the government having to directly lay out a dime to acquire the land. (To be clear, there are other arrangements as well, including the government simply purchasing away the development rights for the land). 56 million acres is about double the combined area of every National Park in the lower 48 states.
These preserved lands serve as wildlife habitats, migration corridors, and recreational trails for humans. They foster the growth of healthy forests, and (by seriously limiting construction and traffic), generally improve water quality in streams and creeks. Conservation easements are one of the greatest tools we have to incentivize land-owners to exchange their personal investment for an opportunity to preserve wild-lands and wild-life in perpetuity.
When I first moved to California, probably the first land I fell in love with was the redwood forests, golden (seriously, they're golden) fields, and rolling hills that make up Skyline Ridge. (Skyline is that section of the Santa Cruz mountains that spans the vast wildlands of the Santa Cruz Mountains from roughly San Jose to very nearly South San Francisco.) All of this land was acquired and preserved via conservation easements by a group called the Pacific Open Space Trust.
Support the conversation and preservation of wild places, support wildlife, and support the conservation easements that make it possible.
This isn't all of them, but here's an interactive map of some of the conservation easements in the lower 48:
https://www.conservationeasement.us/interactivemap/
https://en.wikipedia.org/wiki/Conservation_easement
https://www.landcan.org/article/Hypothetical-How-a-Conservation-Easement-Works/86/