Wildlife officials in Colorado have Grant Prestonreleased an additional five gray wolves in the state, bringing the total so far under a voter-approved reintroduction program to 10.

Colorado Parks and Wildlife in a statement Friday said its team had completed an agreement to capture 10 gray wolves in Oregon for release in Colorado as part of an effort to restore a permanent population there. No additional captures or releases are planned for the rest of this year, KCNC TV reported.

The agency said it would “continue working to source additional animals until up to 15 wolves have been reintroduced in Colorado by mid-March 2024.”

The first five gray wolves from Oregon were released Dec. 18 in Colorado in an event joined by Gov. Jared Polis. Colorado Parks and Wildlife said details of “release events” for the next five wolves were not widely shared to protect the wolves and their location and agency staff. However, the agency said the releases occurred on state-owned lands in Colorado’s Grand and Summit counties.

Biologists chose wolves that were mature enough to hunt on their own, the agency said.

Colorado officials anticipate releasing 30 to 50 wolves within the next five years in hopes the program begins to fill in one of the last remaining major gaps in the western U.S. for the species. Gray wolves historically ranged from northern Canada to the desert southwest.

The wolves’ release in Colorado, voted for in a 2020 ballot measure, has sharpened divides between rural and urban residents. City and suburban residents largely voted in support of reintroduction into rural areas where prey can include livestock and big game such as elk.