"The color of each state indicates how frequently you will find someone with this surname in each state.
For instance, if a state is colored RED, then 1 in 100 people (or more) in that state have the surname.
Similarly, YELLOW means approximately 1 in 300 have the surname, GREEN means 1 in 1000,
and BLUE means 1 in 10,000 (or less)."

"The sources of the surname data are the 1850 Census, 1880 Census, 1920 Census, and 1990's phone books.
Note that the Census data is a sampling of 1 in 100 names, so the 1990 data is the most accurate."

BOE

ADKINS

LINVILLE

NOTE: This is the result I received for REIGSTAD -- "Our database contains the 50,000 most commonly occurring names in the United States. Unfortunately, the name you selected isn't contained in this database. Try using a slightly different spelling of this name."