# Relationship history for MSHA mine 4104081

Current hierarchy: **Greg D  Boyd; Jamie A  Boyd → Boyd Sand & Gravel Ltd → Backwoods Pit**

- 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:** Mary  Fulton → Backwoods Pit; 1995-02-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Brazos Valley Sand & Gravel Inc → Backwoods Pit; 1999-06-01 to 2002-12-04; source msha-controller-operator-history
- **controller_controls_operator:** Mary  Fulton → Brazos Valley Sand & Gravel Inc; 1999-06-01 to 2002-12-04; source msha-controller-operator-history
- **operator_operates_mine:** Boyd Sand & Gravel Ltd → Backwoods Pit; 2002-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Jamie A  Boyd  et al → Backwoods Pit; 2002-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Jamie A  Boyd  et al → Boyd Sand & Gravel Ltd; 2002-12-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Greg D  Boyd  et al → Boyd Sand & Gravel Ltd; 2002-12-05 to current/open; source msha-controller-operator-history