Exhibit 16.1

Mine Safety Disclosure

In July 2010, the U.S. Congress passed the Dodd-Frank Wall Street Reform and Consumer Protection Act, which requires certain disclosures by companies that are required to file periodic reports under the Securities Exchange Act of 1934, as amended and operate mines regulated under the Federal Mine Safety and Health Act of 1977, as amended (“FMSHA”). The following mine safety information is provided pursuant to this legislation for the our fiscal year ended June 30, 2018.

The Company's Poplar Grove mine is subject to FMSHA. The FMSHA is administered by the Mine Safety and Health Administration (“MSHA”). The Company has complied with FMSHA and MSHA rules and regulations in all material respects, and the Company has had no reportable events under such laws and regulations during this reporting period.

Mine or
Operating
Name

Section
104
S&S
Citation
(#)

Section
104 (b)
Orders
(#)

Section
104 (d)
Citations
and
Orders
(#)

Section
110 (b) (2)
Violations
(#)

Section
107 (a)
Orders
(#)

Total
Dollar
Value of
MSHA
Assessments
Proposed
($)

Total
Number
of Mining
Related
Fatalities
(#)

Received
Notice of
Pattern of
Violations
Under
Section 104(e)
(Yes/No)

Received
Notice of
Potential
to Have
Pattern
Under
Section 104(e)
(Yes/No)

Legal
Actions
Pending
as of
Last Day
of Period
(#)

Legal
Actions
Initiated
During
Period
(#)

Legal
Actions
Resolved
During
Period
(#)

Poplar Grove