# Relationship history for MSHA mine 0504400

Current hierarchy: **Michael J  Pfister; Richard G  Pfister → Golden Cross Aggregates → Golden Gross Mine**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-17T05:35:58.500035+00:00

## Valid-time edges

- **operator_operates_mine:** Sanborn Sand & Gravel Inc → Golden Gross Mine; 1989-07-01 to 2003-07-30; source msha-controller-operator-history
- **controller_controls_mine:** W R  Sandborn et al → Golden Gross Mine; 1989-07-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** W R  Sandborn et al → Sanborn Sand & Gravel Inc; 1989-07-01 to 2003-07-30; source msha-controller-operator-history
- **operator_operates_mine:** Dispersing Aggregate Materials Inc → Golden Gross Mine; 2003-07-31 to 2005-05-10; source msha-controller-operator-history
- **controller_controls_mine:** Stephen M  Mc Evoy → Golden Gross Mine; 2003-07-31 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Stephen M  Mc Evoy → Dispersing Aggregate Materials Inc; 2003-07-31 to 2005-05-10; source msha-controller-operator-history
- **operator_operates_mine:** Golden Cross Aggregates → Golden Gross Mine; 2005-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_mine:** Michael J  Pfister et al → Golden Gross Mine; 2005-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael J  Pfister et al → Golden Cross Aggregates; 2005-05-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Richard G  Pfister et al → Golden Cross Aggregates; 2005-05-11 to current/open; source msha-controller-operator-history