Anderson Poul. Gibraltar Falls

The Time Patrol base would only remain for the hundred-odd years of inflow. During that while, few people other than scientists and maintenance crew would stay there for long at a stretch. Thus it was small, a lodge and a couple of service buildings, nearly lost in the land.
Five and a half million years before he was born, Tom Nomura found that southern end of Iberia still more steep than he remembered it. Hills climbed sharply northward until they became low mountains walling the sky, riven by canyons where shadows lay blue. It was dry country, rained on violently but briefly in winter, its streams shrunken to runnels or nothing as its grass burnt yellow in summer. Trees and shrubs grew far apart, thorn, mimosa, acacia, pine, aloe; around the waterholes palm, fern, orchid.
Withal, it was rich in life. Hawks and vultures were always at hover in cloudless heaven. Grazing herds mingled their millions together; among their scores of kinds of zebra-striped ponies, primitive rhinoceros, okapi-like ancestors of the giraffe, sometimes mastodon — thinly red-haired, hugely tusked — or peculiar elephants...