What level of unit was the predecessor of Northern Shaanxi Mining Bureau?

The predecessor of the Northern Shaanxi Mining Bureau is the Northern Shaanxi Coal Mine Administration Bureau, which belongs to the local administrative unit. Shaanxi Coal Mine Administration Bureau was established in 1950, responsible for the management of coal resources and coal mining enterprises in northern Shaanxi. Later, according to the needs of the national administrative system reform, the Northern Shaanxi Coal Mine Management Bureau was restructured into the Northern Shaanxi Mining Management Bureau. The specific level may need further investigation.