# Relationship history for MSHA mine 0504922

Current hierarchy: **MTFE Holdings; HFI LLC → Miller-HFI, LLC → City of Greeley Gravel 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: 2026-10-18T09:31:49.615908+00:00

## Valid-time edges

- **controller_controls_mine:** Martin Marietta Materials Inc → City of Greeley Gravel Pit; 1950-01-01 to current/open; source msha-controller-operator-history
- **operator_operates_mine:** Miller-HFI LLC → City of Greeley Gravel Pit; 2008-10-13 to 2016-03-17; source msha-controller-operator-history
- **controller_controls_mine:** HFI LLC et al → City of Greeley Gravel Pit; 2008-10-13 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** HFI LLC et al → Miller-HFI LLC; 2008-10-13 to 2016-03-17; source msha-controller-operator-history
- **controller_controls_operator:** MTFE Holdings et al → Miller-HFI LLC; 2008-10-13 to 2016-03-17; source msha-controller-operator-history
- **operator_operates_mine:** Martin Marietta Materials Inc. → City of Greeley Gravel Pit; 2016-03-18 to 2016-07-10; source msha-controller-operator-history
- **controller_controls_operator:** Martin Marietta Materials Inc → Martin Marietta Materials Inc.; 2016-03-18 to 2016-07-10; source msha-controller-operator-history
- **operator_operates_mine:** Miller-HFI, LLC → City of Greeley Gravel Pit; 2016-07-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** HFI LLC et al → Miller-HFI, LLC; 2016-07-11 to current/open; source msha-controller-operator-history
- **controller_controls_operator:** MTFE Holdings et al → Miller-HFI, LLC; 2016-07-11 to current/open; source msha-controller-operator-history