Interior Secretary Ryan Zinke's recommendation that President Donald Trump shrink the boundaries of four national monuments, including the Cascade-Siskiyou, is fraught with factual errors and may be on shaky legal ground.

Zinke's written memorandum, obtained by The Washington Post, doesn't say exactly how much of a reduction is contemplated. The document is labeled "Draft Deliberative — Not for Distribution," indicating that it may be subject to change.

Some changes are in order.

For instance, the memo says the original Cascade-Siskiyou declaration prohibited "motorized transportation" (it didn't). It also urges protection of "hunting and fishing rights." Both hunting and fishing are allowed in the monument.

The memo also asserts that the 1906 Antiquities Act giving presidents the power to create monuments was intended to protect “objects of historic or scientific interest.” Biodiversity, it suggests, is too broad a concept to be considered an "object." The Cascade-Siskyou monument was created and expanded to preserve the diversity of plant and animal species found there.

But the U.S. Supreme Court ruled unanimously in 1920 that the entire Grand Canyon — then a monument — qualified as an "object."

"The defendants insist that the monument reserve should be disregarded on the ground that there was no authority for its creation," Justice Willis Van Devanter wrote. "To this we cannot assent. The act under which the President proceeded empowered him to establish reserves embracing 'objects of historic or scientific interest.' The Grand Canyon ... 'is an object of unusual scientific interest.'"

So is the Cascade-Siskiyou bioregion.