The funds are part of an $8 billion pandemic relief package promised to the Tribes in late March, and were supposed to be distributed by April 26.
Payments totaling $4.8 billion will go to tribes over the next several days, and further payments will go out later, the Treasury Department said.
The corporations are unique to Alaska and own most Native lands in the state under a 1971 settlement but are not tribal governments.
Experts have blamed the lack of internet access in Indian Country and the arrival of the coronavirus for tribes' low Census response rates.
While contractors detonate explosives on public land, lawmakers move to lax regulations for border wall construction on private property.
The U.S. Department of Agriculture is investing $1.6 million in a project to provide more than 1,400 rural Arizonans with high-speed broadband access.
The FCC and Arizona Indigenous communities are working to bridge the digital divide in Indian Country.