In the old days, the seeker had to build the sweat lodge by himself. The seeker then takes his Pipe and some tobacco and goes up the mountain. Helpers have gone ahead and prepared a sacred place. The seeker stays there and prays for a vision. Often it comes in the form of an animal.
Dreams often carry the most powerful visions.
At the end of the Vision Quest, the helpers come and take the seeker down the mountain to the sweat lodge. The holy man listens to everything the seeker has seen and heard and interprets the vision.