# Relationship history for MSHA mine 4102397

Current hierarchy: **Cecil  Dunn Jr; Grayson  Martin → Crosby Sand Llc → CROSBY SAND LLC**

- 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:** Carol Lewis Company → CROSBY SAND LLC; 1950-01-01 to 1978-11-21; source msha-controller-operator-history
- **controller_controls_mine:** Lewis Carol Company → CROSBY SAND LLC; 1950-01-01 to 1978-11-21; source msha-controller-operator-history
- **controller_controls_operator:** Lewis Carol Company → Carol Lewis Company; 1950-01-01 to 1978-11-21; source msha-controller-operator-history
- **operator_operates_mine:** Seabrook Sand Inc → CROSBY SAND LLC; 1978-11-22 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_mine:** Robert  Walsh et al → CROSBY SAND LLC; 1978-11-22 to 1980-02-28; source msha-controller-operator-history
- **controller_controls_operator:** Robert  Walsh et al → Seabrook Sand Inc; 1978-11-22 to 1980-02-28; source msha-controller-operator-history
- **operator_operates_mine:** Seabrook Sand Company → CROSBY SAND LLC; 1980-03-01 to 1989-03-27; source msha-controller-operator-history
- **controller_controls_mine:** Paul  Hester → CROSBY SAND LLC; 1980-03-01 to 1989-03-27; source msha-controller-operator-history
- **controller_controls_operator:** Paul  Hester → Seabrook Sand Company; 1980-03-01 to 1989-03-27; source msha-controller-operator-history
- **operator_operates_mine:** Best Sand Company → CROSBY SAND LLC; 1989-03-28 to 2000-04-17; source msha-controller-operator-history
- **controller_controls_mine:** John D  Bertling → CROSBY SAND LLC; 1989-03-28 to 2000-04-17; source msha-controller-operator-history
- **controller_controls_operator:** John D  Bertling → Best Sand Company; 1989-03-28 to 2000-04-17; source msha-controller-operator-history
- **operator_operates_mine:** Crosby Sand Llc → CROSBY SAND LLC; 2000-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Cecil  Dunn Jr  et al → CROSBY SAND LLC; 2000-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Cecil  Dunn Jr  et al → Crosby Sand Llc; 2000-04-18 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Grayson  Martin  et al → Crosby Sand Llc; 2000-04-18 to current/open; source msha-controller-operator-history