Nagano Niigata Area Pass to Kisofukushima?

Dear Community,

I'd like to travel to Kiso-Fukushima from Tokyo-Area and am currently sorting out travel options.
Depending on the trains taken, a "JR East Nagano Niigata Area Pass" would be cheaper than the regular out- and inbound fares.

I am not sure, if the total distance to Kiso-Fukushima is covered by this pass.
As Kiso is in Nagano prefecture (according to google) and the pass covers this prefecture (according to the website), it should - at least to my understanding.

However, my local travel bureau (which is specialized on japan-travel and sells passes) would neither confirm nor deny this as they simply don't know.....
The routes pointed out on the official website also only show the line between Matsumoto and Chino (however this may be due to the fact that the route to Kiso is just a minor one).

Any ideas on this?
Best regards
Jan

The pass is only valid as far as Shiojiri. You would have to pay separately for the fare beyond Shiojiri, which is 770 yen one way by local train or around 1500-2000 yen one way by limited express train.

A map of the pass' coverage area can be seen here:
https://www.japan-guide.com/e/e2361_nagano_niigata.html

The pass' coverage area is based on the service area of the JR East company rather than prefectural borders. Shiojiri is the border station between JR East and JR Central.

Thank you Uji, you are always a big help.

I've seen that map but as written was confused about the Nagano-prefecture bit.