Dakota: verbs with 'hill' involved

["Alfred W. Tüting"]

Can anybody plz enlighten me with the construction (etymology?) of those
one-word-sentences all involving the idea of 'hill'? (I'm aware of the
verbs included as there are _gli_, _hi_ etc., and the affixes' _a-_,
_e-_ (a + i ?) functions). But what is the meaning of the remaining
_yahaN_? Can it be broken down to _ya_ etc. and what does it mean?
(Buechel gives _yahaN_  in a meaning - see last entry below! - that
doesn't seem to be etymologically connected to the  idea of 'hill', does
it? Or am I missing anything?

gliya'hAN
to appear on top of a hill in sight on one's way home

agli'yahAN
they came up a hill and stopped in sight on their way home

e'yahAN
they go up a hill and stand on

hiya'hAN
to appear on top of a hill, so becoming visible; said in ref. to one

ahi'yahAN
they came up (...) a hill and stood in sight

agli'yoxpayA
they came down from a hill

ahi'yoxpayA
they came down a hill

ai'natxagya
beyond a hill

yahaN'
to prick or run into one, as a splinter, thorn etc

Thanks in advance

Alfred