# Relationship history for MSHA mine 2402742

Current hierarchy: **Bruce  Barth; Marie  Barth → Montana Frontier Sandstone → Jones Quarry**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-13T11:19:05.459773+00:00

## Valid-time edges

- **controller_controls_mine:** Bruce  Barth et al → Jones Quarry; 2017-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Montana Frontier Sandstone → Jones Quarry; 2019-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Bruce  Barth et al → Montana Frontier Sandstone; 2019-05-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Marie  Barth et al → Montana Frontier Sandstone; 2019-05-13 to current/open; source msha-controller-operator-history