When a vocab is a single kanji all alone with no okurigana (hiragana attached to the kanji) it's usually going to be the kun'yomi reading, which you didn't learn when you learned the kanji. To remember this word's reading we'll use a mnemonic.
What are you doing going up into the mountains? You're hunting for yams (やま). Go ahead, imagine yourself doing just that, climbing up the mountain (it's hard work!) and then digging in the ground with your hands, then pulling up that sweet, delicious yam! Mmm!
I'll climb a mountain with my friends.
This is the world's biggest man-made mountain.
At 8 am, let’s meet naked on Bald Mountain.