# Relationship history for MSHA mine 4104890

Current hierarchy: **Myrna  Pierce; Howard K  Pierce → Howard Pierce & Sons Stone Company, LLC → San Saba 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:** Myrna  Pierce et al → San Saba Pit; 2009-04-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Howard Pierce & Sons Stone Company, LLC → San Saba Pit; 2011-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Myrna  Pierce et al → Howard Pierce & Sons Stone Company, LLC; 2011-06-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Howard K  Pierce et al → Howard Pierce & Sons Stone Company, LLC; 2011-06-13 to current/open; source msha-controller-operator-history