What I seek
There is a Norwegian-language wikipedia article titled Helleristningen i Vågan.
What I found
Unfortunately, there isn't an English version, the Google Translate-ed version is here.
The carving is approx. 200 meters north of highway 80 , approx. two kilometers east of Reitan . Information sign at the rest area on site.
There is no source directly quoted for this claim though. The corresponding Finnish Wikipedia page makes the same claim ("Kalliopiirros sijaitsee noin 200 metriä tieltä 52 metrin korkeudessa."), but cites a page saying "The page was not found" ("Siden ble ikke funnet").
The External links ("Eksterne lenker") section of the Norwegian page points to a kulturminnesok page, with this map:
Road 80 is there, that's a good sign. The marked location, given the scale in the lower left corner, seems to be closer to 300 than to 200 meters to me.
I align the kulturminnesok map with Google Maps:
I find that the deer should be the marker I placed on that map above link to google maps with that area in focus..
What makes me unsure
When I look at Road 80 on Street View in the vicinity of the approximated location, the only clue I find that something might be there is this narrow path:
I don't find any "rest area on site", yet alone "Information sign at the rest area on site", as suggested by the translated Norwegian Wikipedia article.
Satellite view from above:
Again, nothing which would suggest that there is a historical site there.
The question is, is the deer painting the Wikipedia articles mentions, actually there? ie roughly at the location I figured using Google Maps? Will following that path from Road 80, which I screenshoted above, take me to that deer?