Could you please explain what the meaning of "be tended on horseback" is?
The text is here:
When Grandpa-down-the-hill was a young man, there’d been herds of livestock spread across the mountain, and they were tended on horseback.
Educated by Tara Westover
...there had been herds of livestock spread across the mountain, and they [the livestock] were tended [that is, cared for] on horseback.
NOAD defines tend as:
tend (verb) care for or look after
So, what that sentence means is:
...there had been herds of livestock spread across the mountain, and they (the cattle) were tended [by men on] on horseback.
In other words: people riding on horses looked after the livestock.
You could have found these things out in a short time by using a dictionary, either printed or online. When Grandpa-down-the-hill was a young man, the cattle spread across the mountain were cared for by people riding on horses. Have you heard of "cowboys" or seen any "Western" cinema films?
cattle noun [ plural ] UK /ˈkæt.əl/ US /ˈkæt̬.əl/ B1 cows and bulls that are kept for their milk or meat:
beef/dairy cattle
https://dictionary.cambridge.org/dictionary/english/cattle
tend verb (CARE) [ T ] formal to care for something or someone:
He carefully tended his sunflower plants. The nurse gently tended the patient's cuts and bruises.
https://dictionary.cambridge.org/dictionary/english/tend
horseback noun UK /ˈhɔːs.bæk/ US /ˈhɔːrs.bæk/ on horseback riding a horse:
police on horseback
https://dictionary.cambridge.org/dictionary/english/horseback
