When the U.S. oil boom hit North Dakota a decade ago, wells sprang up quickly on the edges of the Fort Berthold Indian Reservation, an expanse of prairie and rolling hills three times larger than Los Angeles. Tribe members here, facing a 40 percent unemployment rate and sending their children to 1950s-era school buildings, were eager to tap some of state’s most promising reserves. But layers of federal regulation – applying only to tribal lands – slowed them down for years, frightened away investors and cost them millions of dollars. “The reservation looked like the hole of a donut,” said Marcus Levings, who was chairman of Mandan, Hidatsa and Arikara (MHA) Nation’s reservation at the time. […]