The developer of the high-speed rail line between Dallas and Houston has reached option agreements on about 30 percent of the land estimated to be needed for the bullet train’s route in the 10-county stretch.

Texas Central, the developer, called the acquisition options a “significant milestone” for the controversial project.

Negotiations have resulted in option agreements in all 10 counties, including 50 percent of the parcels for the proposed route in Waller and Grimes counties. Grimes County…