The back mountain is only a barren one, whose pathway is full of stone riprap and overgrown with weeds, rugged and rough, difficult to walk by foot.

后山不过是个虚山，山径乱石野草，崎岖难行。

youdao

We retreated back down the mountain.

我们从山上撤了下来。

《牛津词典》

The dry mountain ranges of the western United States contain rocks dating back 440 to 510 million years, to the Ordovician period, and teeming with evidence of tropical marine life.

美国西部干燥的山脉包含了距今4.4亿至5.1亿年前的奥陶纪岩石，其中充斥着热带海洋生物生存的迹象。

youdao

The road moves back and forth and around corners as it moves up the face of the mountain.

VOA: special.2010.09.08

A man named Fred Dewey wrote to friends back home that it took him two weeks just to move his supplies from Skagway to the mountain.

VOA: special.2009.02.11

Even if the entire ACA is repealed and the snowballs are rolled back up the mountain, I am cheered by the fact that many people out there are creating an avalanche that will change our current paternalistic approach in health care.

FORBES: Can Patients Make Good Decisions?

Before the 8 a.m. bus back down the mountain to the Mediterranean, I stopped at the bakery for fresh bread.

WSJ: Taken Aback by the Kindness of Strangers

In 1995, Smith led a team to bring wolves back to the Rocky Mountain landscape.

CNN: Gray wolf: Still endangered?