El Dorado was a king in his own lands, ruling the native people with a just hand. He had been a most promising disciple of the shamans and had grown beyond even their powers. His travels to other worlds had given him powerful magic and a wise understanding of the ways of the world. He recognized the explorers for what they were. He saw the Technomancers' masters pulling the strings, even though the explorers were ignorant of any wrong-doing - since they were merely representatives of their respectives crowns and universities.
El Dorado had seen their kind before in the guise of the Incan Empire, greedy and domineering, they wanted to hold all the world in their hands, so a secret magical war began. El Dorado marshaled the ancient forces of the land and resisted the Technomancer's efforts to wipe them from the earth. From his city of gold he directed his allies to push back the explorers. The Mokolé joined the fight, rousing their nests. The Balam leapt into the fray, bringing a fury that instilled terror in the hearts of the fiercest mages. As always, the Garou were also there, specially the Black Furies.
All the Fera of the land and even the Black Furies put aside their ideological differences to support the wise mage, but even so it wasn't enough. With much effort the Technomancers finally mapped the city of gold out of existence and El Dorado was shunted into its own realm - his magic fell flat as it was severed from his connection to Gaia. The land reappeared in the Umbra as soon as it faded from the face of the Earth and nothing but dreams about that place remained in the minds of Earth's beings.
In time, the dreams became legends and the legends fueled the greed of mortals. During the early decades of the 20th century El Dorado's magic fed the dreams of archeologist Joseph Herlich and guided him to break the spell and rediscover the valley of the city of gold. Herlech was unknowingly forging a path by his own will and desire. A single arduous path now existed, but it remained hidden in the depths of the Amazonian jungle.
The city is still unknown to many residents of the jungle. With the Amazon War raging on, El Dorado was unsure of what course to take. He only knew that he had to protect the city at all cost. After receiving visions of the future he put himself in a deep ageless sleep with the magical gold dust he had used to coat his body. He slept and used his vast mental powers to leave his body, reincarnating himself in the forms of various animals and living entire lives in enigmatic contact with Gaia. Through this practice, he learned more than he ever thought possible and has grown substantially in power.
El Dorado visited the elders of the Garou Nation in their dreams, advising them of potential risks when he knew of them and warning them that their present course is detrimental to the jungles. While the Garou did not always agree with El Dorado, they understood that he had been very helpful in his own right and would do all they could to assist him should the need rises.
The entrance to the Dorado Realm only opens at night and under normal circumstances it would take years for an explorer to find it. The entrance stands fifteen feet off the floor of the valley, in hole through the sheer stone. The Dorado Realm opens up merely a foot and a half into the stone column. The air there is drier and colder, smelling of cinnamon.
The trail ahead goes through a bridge over a bottomless chasm that stretches a long way towards the horizon on both sides. To the north there is a primordial jungle with impossibly tall trees, inhabited by the strange Ewaipanoma. To the south there's an immense lake that goes on like if it was an ocean. Directly across the aforementioned chasm, a quarter mile or more away lies the city of El Dorado. The city itself is a miraculous sight with buildings made of marble and gold. It is that city that hosts the Sept of Gold of the Black Furies tribe, who act as guardians to the realm.
At the end of Rage Across the Amazon's chronicle, El Dorado was killed in his sleep by Samuel Haight, after Pentex sponsored his leadership over a strike force of First Teams to invade the Dorado Realm. Samuel plunged the Conquistador's Sword into the king's heart and the entire realm instantly withered and was swallowed by the waters of Lake Parima. The Sword itself, a fetish created to steal the magical knowledge of its victims, was overwhelmed by El Dorado's wisdom and collapsed before it could be absorbed by Haight, who had no choice but to flee the assured vengeance from the Black Furies of the Sept of Gold.
In secret to all but a few, El Dorado has survived. He is now reincarnated and living as one with the animal totems.