# Relationship history for MSHA mine 0901104

Current hierarchy: **Richard  Grubb; David  Robinson → Rockmart Slate Corp → Blue Hole 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

- **operator_operates_mine:** Rockmart Slate Corp → Blue Hole Quarry; 1997-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Arnold → Blue Hole Quarry; 1997-07-01 to 2006-03-15; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Arnold → Rockmart Slate Corp; 1997-07-01 to 2006-03-15; source msha-controller-operator-history
- **controller_controls_mine:** Richard  Grubb et al → Blue Hole Quarry; 2006-03-16 to 2021-05-27; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Grubb et al → Rockmart Slate Corp; 2006-03-16 to 2021-05-27; source msha-controller-operator-history
- **controller_controls_operator:** William  Parks et al → Rockmart Slate Corp; 2006-03-16 to 2021-05-27; source msha-controller-operator-history
- **controller_controls_mine:** David  Robinson et al → Blue Hole Quarry; 2021-05-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** David  Robinson et al → Rockmart Slate Corp; 2021-05-28 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard  Grubb et al → Rockmart Slate Corp; 2021-05-28 to current/open; source msha-controller-operator-history