DENVER (AP) — Immigrants who are in the country illegally but have valid Colorado driver's licenses can now renew those licenses online or by mail.

Gov. John Hickenlooper signed into law Tuesday a measure that's designed to boost the ranks of the state's agricultural workforce.

Colorado has issued the driver's licenses since 2014. But they had to be renewed in person every three years at one of just three Department of Motor Vehicles offices devoted to that purpose.

The waiting list for renewals is months long, preventing many workers from driving to their jobs.

The bill's Republican sponsors, Sens. Don Coram and Larry Crowder, argued the economies of their rural western and southern Colorado districts were at stake.

Immigrants who can prove they live in Colorado are eligible for the licenses.