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It's the most powerful agency you've never heard of -- at least, until recently.

The Bureau of Land Management, the nation's biggest landlord, found itself in the spotlight after a high-profile brawl with Nevada rancher Cliven Bundy and another dispute with state officials over the Texas-Oklahoma borderlands.

But the seemingly obscure agency, which is in charge of millions of acres of public land, is no stranger to controversy. History shows the power struggle over property rights and land use is one that's been fought -- fiercely -- ever since the bureau was created.

In the nearly seven decades of its existence, the BLM has struggled to find its footing and exert its power, pitted against a vocal states' rights movement.

"The federal government already owns too much land," Texas Gov. Rick Perry, one of the champions of that modern-day movement, recently told Fox News. He called for the federal government, and by extension the BLM, to "divest itself of a huge amount of this landholdings that it has across the country."

The Bureau of Land Management was formed in 1946, consolidating two now-extinct agencies into one for the purpose of overseeing public land. In the beginning, the BLM mostly focused on livestock and mines. Its mission shifted, though, in the 1970s when it took on the role of mediator between commerce and conservation, and faced a second identity crisis in the 1980s. That's when the so-called Sagebrush Rebellion gained new momentum in its push to return control of federal lands to individual states.

That "rebellion" may be underway once again, as states renew concerns about the amount of land controlled by the BLM. Congress also recently weighed in, with House lawmakers passing a bill in February that would prevent the BLM from buying new land.

Currently, the agency, which falls under the purview of the U.S. Department of Interior, oversees 247.3 million acres -- or about one-eighth of the land in the country.

It also owns 700 million acres of on-shore federal mineral estates.

The BLM is responsible for managing a large spectrum of natural resources. The federal agency regulates logging, mining and fracking practices across the country. It also administers close to 18,000 permits and leases a year held by ranchers who graze their livestock on land managed by the federal government. The permits and leases they issue usually last a decade and can be renewed.

In 2009, regulation of public lands in Western states generated $6.2 billion.

By acreage, the agency's largest stake is in Alaska where it owns 72.4 million acres. Nevada ranks second, with 48 million acres under the BLM, and then Utah, with 22.9 million acres.

In Nevada, rancher Cliven Bundy's recent refusal to hand over his family's cattle to the feds re-ignited the national debate over the BLM's power.

On the heels of that controversy, more than 50 lawmakers from nine Western states came together to protest federal land expansion. The state leaders discussed ways to combine their joint goals of taking control of oil-, timber- and mineral-rich lands away from the federal government.

"It's so much bigger than Bundy. There are issues ... all across the West where the federal government is exerting control over things it was never supposed to control," Utah state Rep. Ken Ivory told Fox News. "The federal government was supposed to be a trustee. They do own the land. They do hold title to the land in trust ... but they have a duty to dispose of the land with all states east of Colorado."

Ivory says he wants the federal government to keep a promise it made in the 1894 Enabling Act that made Utah a state. He argues that public lands, except for congressionally designated national parks and wilderness areas, should be transferred back to the states.

So far, state lawmakers in Idaho, New Mexico, Arizona, Nevada, Wyoming, Oregon and Washington are looking for ways to transfer land management back to the states.

Utah, though, has been the most successful. Lawmakers there passed a measure demanding the federal government extinguish title to federal lands, aside from national parks. Ivory was also the primary backer of the 2012 Transfer of Public Lands Act which established a model for the transfer of certain federal lands to the state in the coming years.

The Bundy case has been largely viewed as the first leadership test for new BLM Director Neil Kornze, who was confirmed by the U.S. Senate and sworn into office in April. The local land-use dust-up fed into a growing apprehension over just how much authority the BLM has and how far it is willing to go to maintain control.

In Texas, Attorney General Greg Abbott sent a letter to Kornze looking into allegations the BLM was eyeing a massive land grab in northern Texas. "Decisions of this magnitude must not be made inside a bureaucratic black box," wrote Abbott, a GOP gubernatorial candidate.

The agency indicated that the land in question was determined to be public property. "The BLM is categorically not expanding Federal holdings along the Red River," a BLM spokeswoman said in a written statement.

Attention on the Bundy-BLM battle has lately turned to racially insensitive remarks that Bundy made in several media interviews and appearances.

Conservative and libertarian lawmakers like Kentucky Sen. Rand Paul and Texas Sen. Ted Cruz, initially came to Bundy's defense, calling his situation the latest example of big government overreach.  Both, though, have since scaled back their comments in light of Bundy's remarks.

"Senator Paul spoke out against federal over-regulation and BLM handling of a situation," Paul spokesman Doug Stafford said in a written statement. "He has never spoken to or met Mr. Bundy and is not responsible for the vile comments that come out of his mouth."

Others say Bundy was at fault, failing to pay $1.1 million in fees for letting his cattle graze on government grass for more than two decades.

"I wish Mr. Bundy would mind his law requirements and not try to play to the television cameras about confronting the evil federal government," former BLM director Patrick Shea told KSL TV. Shea has been on both sides of the land-use debate. He represented activist Tim DeChristopher who took on the BLM over the 2008 sale of controversial oil and gas leases in Utah.

The BLM has run into trouble elsewhere.

In March, BLM officials rounded up a horse herd in Wyoming after area ranchers and farmers complained that the herd grazed down pastures and damaged cattle rangeland. The horses were turned over to Wyoming officials. The state then quickly sold all 41 horses to a Canadian slaughterhouse. Animal rights groups protested the sale and slaughter.

A year earlier, BLM agents in Nevada announced they would be removing 50 wild horses from a herd that had grown too large to be sustained.

But the complaints go beyond horses. In 2011, several Utah counties filed a lawsuit against the agency over exceeding its authority by establishing wilderness protections without the consent of Congress.

Back in the nation's capital, House lawmakers passed a package in February that includes a collection of public land access and restoration provisions. They also adopted two amendments that extend the length of grazing permits on federal lands to 20 years from 10 years and also allow expired or transferred permits to remain effective until new ones can be issued.

Calls to the BLM for comment were not returned.