# Relationship history for MSHA mine 2901900

Current hierarchy: **Paul  Parker → San Pedro Sand and Gravel → San Pedro Rock Portable Plant #1**

- 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:** San Pedro Gravel Inc → San Pedro Rock Portable Plant #1; 1983-01-01 to 1999-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Thomas W  Freeman et al → San Pedro Rock Portable Plant #1; 1983-01-01 to 1999-03-19; source msha-controller-operator-history
- **controller_controls_operator:** Thomas W  Freeman et al → San Pedro Gravel Inc; 1983-01-01 to 1999-03-19; source msha-controller-operator-history
- **controller_controls_mine:** Paul  Parker → San Pedro Rock Portable Plant #1; 1986-11-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** San Pedro Rock Llc → San Pedro Rock Portable Plant #1; 1999-03-20 to 2001-10-04; source msha-controller-operator-history
- **controller_controls_mine:** Joe  Mauzy et al → San Pedro Rock Portable Plant #1; 1999-03-20 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Joe  Mauzy et al → San Pedro Rock Llc; 1999-03-20 to 2001-10-04; source msha-controller-operator-history
- **controller_controls_operator:** Eddie  Mauzy et al → San Pedro Rock Llc; 1999-03-20 to 2001-10-04; source msha-controller-operator-history
- **operator_operates_mine:** San Pedro Sand and Gravel → San Pedro Rock Portable Plant #1; 2001-10-05 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Paul  Parker → San Pedro Sand and Gravel; 2001-10-05 to current/open; source msha-controller-operator-history