# Relationship history for MSHA mine 4503603

Current hierarchy: **Heidi A  Grooms → A & E LLC → Skaglund 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:** Skaglund Quarry → Skaglund Quarry; 2006-06-01 to 2007-11-29; source msha-controller-operator-history
- **controller_controls_mine:** Steve A  Skaglund → Skaglund Quarry; 2006-06-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Steve A  Skaglund → Skaglund Quarry; 2006-06-01 to 2007-11-29; source msha-controller-operator-history
- **controller_controls_mine:** Heidi A  Grooms  et al → Skaglund Quarry; 2006-10-10 to 2018-03-20; source msha-controller-operator-history
- **operator_operates_mine:** A & E LLC → Skaglund Quarry; 2007-11-30 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidi A  Grooms  et al → A & E LLC; 2007-11-30 to 2018-03-20; source msha-controller-operator-history
- **controller_controls_operator:** Kris E  Wright  et al → A & E LLC; 2007-11-30 to 2018-03-20; source msha-controller-operator-history
- **controller_controls_mine:** Heidi A  Grooms → Skaglund Quarry; 2018-03-21 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Heidi A  Grooms → A & E LLC; 2018-03-21 to current/open; source msha-controller-operator-history