As election officials count votes in Alaska’s first-ever statewide election by mail, they have rejected thousands of submitted ballots, including one in six from a Western Alaska state House district, causing concern from observers who say the state’s process is disenfranchising voters, particularly Alaska Natives.

At last week’s meeting of the National Congress of American Indians in Anchorage, Michelle Sparck delivered a speech on behalf of a group whose mission is to improve Alaska Native voting rates.

When she described the issue, “there was a gasp in the audience. I think people are reali...