I know that you can't ask questions about recent events, so hopefully I am not crossing any lines, but I am mainly interested in the history of the Federal Government's claim to the land both held by the Bureau of Land Management and the Wildlife Reserve, which have now come under fire.
I did a bit of research myself, and found the wildlife reserve was founded by Teddy Roosevelt's executive order 929 which defines the area and title of the reserve.
But that document doesn't state how.
Did the government already have right to the land? Did they have to purchase it from private parties? Or did they simply not recognize any legal ownership and claimed stake to it?
I wasn't able to find much about the land currently owned by the BLM, so I am also greatly interested in that. Or anything else that closely relates to my rambling questions.
As to how the federal government came to own the land, you have to remember that the United States is the product of colonialism, and less than two centuries ago all the territory in question belonged to indigenous people.
Specifically, the land around Malheur Lake was peopled by the Northern Paiute (a.k.a. Snake Indians), who tended to allot their territories according to access to lake resources. The Paiute had been in contact with Euro-Americans since at least the early 19th century (as the French name of the lake suggests: French-Canadian employees of the Hudson’s Bay Company had homes along the Columbia River), but it wasn’t until the 1860s that these contacts led to conflict.
As more white settlers flooded the Great Basin as they made their way along the Oregon Trail, and miners became increasingly interested in the resources of central and eastern Oregon, conflicts between Paiutes and Americans led to a series of wars – the Pyramid Lake War, the Owens Valley Indian War, and the Snake War. The strains that a growing numbers of white settlers placed on local resources caused many Northern Paiutes to withdraw to remote areas, but some decided to mount a military resistance – which was the cause of these wars.
The final act of these military conflicts was the Bannock War of 1878, in which the U.S. Army decisively defeated Paiute and Shoshone forces in present-day Idaho. Following the war, indigenous people in the region were forced into reservations, with their movements sharply restricted. One group of Northern Paiutes had lived in the Malheur Indian Reservation in eastern Oregon during the 1870s, but after the Bannock War they were forced to move the Yakama Reservation in Washington, or eke out a living as laborers for their white neighbors.
Once the Paiute were removed, ranchers and settlers began to graze their herds of sheep and cattle in the meadowlands around the Malheur Reservation, and the U.S. Army was reluctant to prevent them from doing so. So this was essentially federal land – though the conquest of the Northern Paiute – but in practice, settlers developed a usufruct claim through continued use. Note, however, that these ranchers were not independent operators, but were typically employed by cattle barons who controlled the water supply of the region.