Julia Roberts was the first choice to play Margaret but reportedly refused to take a pay cut, so Sandra Bullock took over the role. That was the second movie in the same year in which Julia Roberts was offered a leading role, turned it down, and the role going to Sandra Bullock. The other movie was "The Blind Side".
Sandra Bullock plays a Canadian who wants to marry her assistant (Ryan Reynolds) in order to keep her Visa status in the U.S. and avoid deportation to Canada. In real life, Reynolds is from Canada and Bullock is from the U.S.
Nowhere does it list Alaska as an actual film location. The film was actually filmed in Boston and on Boston's North Shore. In one of the scenes, you can see the famous Rockport icon, "Motif No. 1," the little red shack famous for being a subject of many famous painters' and photographers' work. Snow-capped mountains (or any mountains, for that matter) are nowhere to be found on the North Shore. Those were added in digitally.
225 Franklin St., Boston, was the real location of The Colden Books office. The entire main office, including Margaret's and Bob's offices, were completely rebuilt and replicated at Disney Studios in Burbank, CA for pickups and re-shoots in January 2009.
"Downtown" Sitka is actually Rockport, Massachusetts, which includes a famous tourist area called Bearskin Neck. The harbor formed by the Neck is where Motif #1 is located. Rockport remains a working fishing village, especially for lobster, although the bigger fisheries are in nearby Gloucester. The filming was done in April, which is off season for large numbers of visitors. Bullock and Reynolds were seen shopping locally.
In this movie, the mother (played by actress Mary Steenburgen) was in the original Parenthood movie as a main female mother character. Then, the father (played by actor Craig T. Nelson) was in the Parenthood TV series as the main patriarch of the family.