Troy Mine Revegetation Services

The Troy Mine is a closed silver mine owned by Troy Mine Inc., located in Lincoln County, Montana. The mine site consists of mine and service adits, mill buildings, shops and office buildings, water and tailings pipelines, a powerline, and a tailings storage facility. Herrera was hired by Troy Mine Inc. to perform revegetation services on approximately 330 acres at the Troy Mine tailings storage facility (TSF) from 2017- 2019. This work was divided into three phases.

In 2016, Herrera hired a contractor to collect tree and shrub seed and to produce over 70,000 seedlings for the first phase of planting, and 114,000 seedlings for the second and third phases of planting. Nursery inspections were conducted to ensure that plant materials met specifications and required quantities. In the spring of 2017, Herrera wrote specifications for salvaging trees from soil stockpiles and provided oversight for the salvage of 130 trees used to provide patches of larger trees on the TSF.

Phase I seeding was completed in the fall of 2017, followed by Phase I planting in the spring of 2018. A total of approximately 147 acres was seeded with native grass and forb seed, and 71,208 nursery stock trees and shrubs were planted over approximately 124 acres during Phase 1. The Phase II portion of the TSF (Cell 4) was seeded and planted in the fall of 2018. Approximately 33 acres were seeded with native grass and forb seed, A 1-acre test plot was seeded with only green alder seed, and 17,790 nursery stock trees and shrubs were planted over 30 acres during Phase II.

Phase IIb revegetation was completed in the fall of 2019 and included seeding approximately 155 acres with a native seed mix and planting approximately 84,859 nursery stock tree and shrub seedlings over 115 acres. Herrera provided oversight of all Phase I , Phase II, and Phase IIb revegetation efforts to confirm specifications were met. Weed inventory and mapping was conducted by Herrera in the spring, summer, and fall of 2017, 2018, and 2019.