Internal watchdog will investigate Zinke’s Montana land deal tied to Halliburton

The Interior Department’s internal watchdog will probe Secretary Ryan Zinke’s role in a land deal backed by the chairman of one of the world’s largest oil field companies. The announcement follows a week of growing demands from Democrats calling for an investigation into Zinke’s involvement with the deal.

In a letter released Thursday by House Democrats, Interior Deputy Inspector General Mary L. Kendall wrote that the department’s watchdog office would ...