# Relationship history for MSHA mine 0103227

Current hierarchy: **HBM Holdings Company → MLC → MLC - Calera**

- Valid-time bounds: inclusive, date granularity
- Null end: open-ended in the upstream history row; not independent proof of present control
- Transaction-time observation: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Margaret J  Heckman  et al → MLC - Calera; 1950-01-01 to 2022-09-06; source msha-controller-operator-history
- **operator_operates_mine:** Peak Lime, Inc. → MLC - Calera; 2001-12-15 to 2007-08-08; source msha-controller-operator-history
- **controller_controls_mine:** Michael R Boyce → MLC - Calera; 2001-12-15 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Michael R Boyce → Peak Lime, Inc.; 2001-12-15 to 2007-08-08; source msha-controller-operator-history
- **operator_operates_mine:** Covia Lime LLC → MLC - Calera; 2007-08-09 to 2019-07-31; source msha-controller-operator-history
- **controller_controls_mine:** S C R-Sibelco Nv et al → MLC - Calera; 2007-08-09 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** S C R-Sibelco Nv et al → Covia Lime LLC; 2007-08-09 to 2019-07-31; source msha-controller-operator-history
- **operator_operates_mine:** MLC → MLC - Calera; 2019-08-01 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** Margaret J  Heckman  et al → MLC; 2019-08-01 to 2022-09-06; source msha-controller-operator-history
- **controller_controls_mine:** HBM Holdings Company → MLC - Calera; 2022-09-07 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** HBM Holdings Company → MLC; 2022-09-07 to current/open; source msha-controller-operator-history