First emigration to USA from Fitjar Norway

Nils Vinnes or Vindnaes came to America from Norway around 1911 the first time than had to return to Norway because his father (Solomon) died, I think in WWI. Nils returned to the US when he was about 21 and resided in St. Paul Minnesota. I beleive I found his second trip to USA through Ellis Island but I can't seem to find his first trip. How can I find this? Michelle