T-Mobile’s 4G LTE network is growing again.

T-Mobile today flipped the switch on its first 600MHz LTE cell sites. The sites are now live in Cheyenne, Wyoming, with plans to activate 600MHz LTE coverage in many other parts of the U.S. later in 2017.

The areas that’ll be getting 600MHz LTE coverage from T-Mobile this year include:

Wyoming

Northwest Oregon

West Texas

Southwest Kansas

The Oklahoma panhandle

Western North Dakota

Maine

Coastal North Carolina

Central Pennsylvania

Central Virginia

Eastern Washington

Unfortunately, there are currently no T-Mobile phones that support this 600MHz LTE coverage, so T-Mo customers will have to wait to try out this new coverage for themselves. That wait won’t be long, though, because T-Mobile says that it’ll have Samsung and LG phones that support 600MHz LTE in Q4 2017.

T-Mobile spent a cool $7.99 billion on its 600MHz spectrum in an FCC auction earlier this year, coming away with an average of 31MHz nationwide that T-Mo says covers 100 percent of the U.S. The 600MHz airwaves will be used for 5G coverage in addition to 4G LTE, but it’ll be a couple of years before we start to see any 5G service deployments.