How to translate this sentence?

[Ashirogi]

This sentence:
ある日 くまの せなかに のって 山道を 行くと 川のところで 動 物たちが こまって いました。

I couldn't make head or tail of this. せなか means back of body, so how does this fit?
My translation:
One day, the bear to get on the (back of his body) went by a mountain road to the river site (with the) animals.
No idea what こまって いました means. Does it mean "went with the"?
I'm doing something wrong -_-...

 

[Toritoribe]

The subject is not the bear. Someone/Something is riding on the bear's back.
Look up 困る in the dictionary.

 

[Ashirogi]

Ohh, "One day, he went on the bear's back with the other animals via the mountain route to the river site but got troubled." Is that accurate?

 

[VarickT]

Sounds more like, "One day, riding on the bear's back (I/he/she/they) went up the mountain path. At the river, the animals were troubled."

 

[Toritoribe]

@ The OP, you don't seem to understand the functions of the -te form "のって" and conditional clause "いくと" yet. Have you learned them?

 

[Ashirogi]

Seems I haven't. I'll go read up on those.

 

[Toritoribe]

Well, it's better to do so before starting translating a text. Those are very basic structures learners must understand.

 

[Mike Cash]

Seems I haven't. I'll go read up on those.

You would do well to go through at least a couple of beginner/intermediate textbooks thoroughly before attempting to translate. There is more to it than just looking stuff up in a dictionary and guessing.