Setting the Stage for Sustainable Development

OSISKO MINING

SUSTAINABLE DEVELOPMENT REPORT 2017 SETTING THE STAGE FOR SUSTAINABLE

1DEVELOPMENTSUSTAINABLE DEVELOPMENT REPORT 2017 TABLE OF CONTENTS

A letter from Osisko Mining 3 Who is Osisko Mining? 4 2017 At a Glance 5 Our projects 7 Governance 8 Our team 11 Awards 10 Sustainable development action plan 12 Health & Safety 13 Osisko Mining society 16 Environment 7 Economy 13 Contact us 17

Windfall Lake Project

2 SUSTAINABLE DEVELOPMENT REPORT 2017 Osisko Mining’s 2017 Sustainable Development plant. We continued our stakeholder A letter Report provides information about our engagement, holding more than 65 meetings in from Osisko Mining governance, our vision for the future and our host communities to share information on the status of our key projects. We also share the projects. information on four key components of In 2017, we acquired claims that consolidated sustainability: health and safety, society, the our position in the Lebel-sur-Quévillon area. environment and the economy. The Quévillon Project includes about 30 known The focus in 2017 was on establishing the gold showings as well as the historic Osborne- groundwork for achieving our sustainable Bell gold deposit, 17 kilometres northwest of development objectives. We developed an Lebel-sur-Quévillon. occupational health and safety management Osisko Mining prides itself on creating value system, implemented our spill management for our stakeholders, partners and community plan, conducted drill pad reclamation, stakeholders through our sustainable practices. established donation and sponsorship We are continuously looking for new and guidelines reflecting our core values, and innovative ways to minimize our effect on the focused on hiring employees from local environment by conserving natural resources communities and utilizing local contractors with and consumable goods and minimizing our Aboriginal joint venture partnerships. environmental footprint through progressive The Windfall Lake Project attracted much of rehabilitation measures. Furthermore, building our attention this year. We built and restored long-term positive relationships with our host underground and surface infrastructure. We communities allows Osisko Mining to invest completed dewatering of the exploration ramp in community-focused sustainability projects in late August and took our first underground while creating local jobs and promoting local blast in the exploration ramp in October. We purchases. initiated the environmental approval processes We would like to thank the people and by filing the project description with the federal organizations who support us, including our government and the preliminary project employees, First Nations, host communities, notification with the Québec government. financial and government partners, and our Osisko Mining also identified a site near shareholders. Lebel-sur-Quévillon for a potential processing Sincerely,

@ The Sustainability Development Report includes information from John F. Burzynski Alexandra Drapack January 1 to December 31, 2017. President, CEO and Director Vice-President, Environment Services The 2016 report is available at and Sustainable Development osiskomining.com. 3 SUSTAINABLE DEVELOPMENT REPORT 2017 OUR COMPANY

Who is Osisko Mining?

Osisko Mining is an exploration and development company with a focus on precious metal resources in Canada. We explore in Québec and Ontario, looking for opportunities to enhance shareholder value. Our flagship asset is the Windfall Lake Project in northern Québec.

OSISKO MINING BY THE NUMBERS

2017 2016 TSX OSK OSK Shares outstanding ±$208M $162M Fully diluted shares ±$250M $190M Fully diluted cash ±$315M ±$140M Market capitalization ±$705M $395M Debt $0 $0 Equity ±$428M N/A Net revenues $0 $0 Cash and investment $191M ±$117M Total Workforce 173 73

Windfall Lake Project 2017 2016 Mining claims 12,400 ha 12,400 ha Total drilled 386,596 m 106,000m Spent $104M $22M

John Burzynski, President and CEO, Windfall Lake core shack

4 SUSTAINABLE DEVELOPMENT REPORT 2017 OVERVIEW

2017 At a glance

Osisko Mining’s projects Osisko Mining holds Project Location Status Activity in 2017 In 2017, Osisko Mining drilled: • A 100 per cent interest in the high-grade Windfall Lake Québec Owned 100% Drilling, exploration ramp, camp capacity • 386,596 metres on the Windfall Lake Project Windfall Lake gold deposit on the Eeyou Urban Barry Québec Owned 100% Drilling • 27,595 metres on the Urban Barry Project Istchee James Bay territory in northern Black Dog (Souart) Québec Owned 100% Compilation, surveys and drilling • 2,928 metres on Marban Block Project Québec Quévillon Québec Owned 100% Surveys and drilling • 1,575 metres on the Quévillon Project • A 100 per cent undivided interest in a large Garrison Ontario Owned 100% Drilling • 59,682 metres on the Garrison Project in area of claims in the Urban Barry area and Marban Block Québec Owned 100% Drilling northern Ontario nearby Quévillon area (more than 3,300 Malartic Block Québec Owned 100% Surveys square kilometres) Siscoe East Québec Owned 100% None Osisko Mining has four main deposits • A 100 per cent interest in the Marban Project Héva Québec Owned 100% Surveys containing an aggregate of 3.42 million ounces in Québec’s prolific Abitibi gold mining Kan Québec Earn-in Surveys and mapping and drilling of global resources in the measured and district Eléonore Regional Québec Earn-in Surveys and mapping indicated mineral resource categories, and an • Properties in the Larder Lake Mining Division Eléonore JV Québec Earn-in Surveys aggregate of 1.8 million ounces in the inferred in northeast Ontario, including the Jonpol James Bay Québec Earn-in Surveys and drilling mineral resource category. and Garrcon deposits on the Garrison Project, the Buffonta mine and the Gold Pike Mine Project • Interests and options in additional properties in northern Québec and Ontario

2017 MILESTONES Windfall Lake Project Other exploration projects

January March April June July August October November December • On-going drilling • Received transfer • Identified a • Filed Project • Received federal • Increased the scale • First undergrpound • First Open House in • Sale of the Swayze of the certificate of potential site for Description and and provincial of the ongoing drill blast at the Waswanipi Project • Binding agreement authorization for a future mill near Premilinary Project guidelines program exploration ramp with Barrick Gold the bulk sample Lebel-sur-Quévillon Information reports • Began the • Added 400,000 • First Open House in • Sale of the Corp. on the Kan on Windfall Lake for Windfall Lake Environmental meters of drilling Lebel-sur-Quévillon Catherine and Project Project Project Assessment (global total of De Santis Projects • Updated the site 800,000 meters) restoration plan • Collaboration • Significant land Agreement with acquisition for the Lebel-sur-Quévillon Quévillon Project

5 SUSTAINABLE DEVELOPMENT REPORT 2017 Our projects

WINDFALL LAKE PROJECT GARRISON PROJECT The Windfall Lake Project consists of 285 Throughout 2018, Osisko Mining will explore The Garrison Project is located in Garrison No drilling occurred on the Jonpol Project in contiguous mining claims covering about the extension of the known gold zones, and Township, Ontario. During 2017, Osisko Mining 2017. 12,400 hectares located between Val-d’Or and will begin exploration for new mineralization. drilled 59,682 metres in 151 drill holes. The The 2018 drilling campaign will start in May, Chibougamau in the Eeyou Istchee James Bay Underground work will focus on collecting drilling program focused on the 903 zone, focusing on the west extension of the Jonpol territory, Québec. The Windfall Lake Project a bulk sample (for metallurgical testing and which significantly expanded the known zone and possible new targets in the eastern gold deposit is one of the highest-grade grade confirmation), underground mapping mineralized zone to the southwest, northwest portion of the property. An updated resource resource-stage gold projects in Canada. Our and underground exploration drilling. We and south. The rest of the program was will be completed in 2018. ongoing drill program at Windfall Lake has 18 will release an updated resource during the dedicated to infill drilling on the Garrcon drill rigs focused on the main and adjacent second quarter and will complete a preliminary Project. Lynx deposits and two additional rigs working economic assessment in Summer 2018. on regional targets. The 800,000-metre drill program combines definition, expansion and exploration drilling in and around the main Windfall gold deposit and the Lynx deposit.

EXPLORATION RAMP ADVANCEMENT In 2007, advancement of an underground exploration ramp was initiated for the purpose of collecting a bulk sample. The project was discontinued before completion and the ramp was allowed to flood with water. In 2017, Osisko Core at Windfall Lake Project Mining received government approval for a mine water treatment system. This certificate of authorization allowed Osisko Mining to dewater the ramp to conduct advanced exploration by extending the exploration ramp. Marban Block Project Work on the exploration ramp has begun and Windfall Lake Project the portal has been restored. Underground Urban Barry Project infrastructure and excavations completed Quévillon Project during 2017 include 1,021 metres of Garrison Project rehabilitation and 136 metres of new exploration The exploration ramp portal rehabilitation at Windfall ramp advancement towards Zone 27 and Lake Project is complete. Caribou and 93 metres of general underground infrastructure.

6 SUSTAINABLE DEVELOPMENT REPORT 2017 Osisko governance

Good corporate governance is key to Osisko Mining’s long-term success and the protection of our stakeholders’ interests. We are committed to improving our governance according to best practices and regulatory guidance.

Shareholders elect Osisko Mining’s board Osisko Mining’s Board of Directors has of directors, who have vast experience and approved our corporate governance guidelines, expertise in exploration, metallurgy, mining, which promote its effective function and accounting, legal, banking, financing and set expectations for the performance of its securities. In fulfilment of our 2016 sustainable responsibilities. We have also adopted a code development goal of promoting diversity and of ethics, which governs the behaviour of all equity within our workforce, Osisko Mining employees, management and directors. was proud to appoint Amy Satov to the Board of Directors. The appointment is a first step The following committees support the Board: towards Osisko Mining’s commitment to • Audit committee include women at all levels of the organization. • Corporate governance and nominating committee • Compensation committee • Health, safety and environment and corporate social responsibility committee

Drill at Windfall Lake Project

7 SUSTAINABLE DEVELOPMENT REPORT 2017 OUR EMPLOYEES

Our team

Osisko Mining strives to attract a high-quality, diversified workforce, from the field staff to the Board of Directors, by providing:

• Above-average compensation bench Osisko Mining encourages employees marked against our peers in the to participate in training programs, and mining and exploration industry develops new talent through student • •Benefits to protect permanent internships and engagement with local employees and their families universities. • Long- and short-term incentive programs In 2017, the • Opportunities for personal growth Osisko Mining workforce Distribution of employees by place included 36% of residence women

Other regions of Québec 48%

Abitibi 17%

Lebel sur Quévillon 6%

Nord-Du-Québec 11%

Ontario 18%

2017 2016 Workforce Male Female Male Female Board of Directors 8 (89%) 1 (11%) 10 (100%) 0 (0%)

2017 2016 Workforce Male Female Male Female Management 8 (73%) 3 (27%) 9 (90%) 1 (10%) Employees 103 (64%) 59 (36%) 39 (61%) 25 (39%) Total 111 (64%) 62 (36%) 47 (64%) 26 (39%) 173 73

Betsy Shecapio, Waswanipi Community Liaison Advisor, Windfall Lake Project 8 SUSTAINABLE DEVELOPMENT REPORT 2017 OUR TEAM

Our 2017 workforce included 173 Aboriginal workers employees, 36 per cent of whom In 2017, Osisko Mining worked with Aboriginal were female. All our employees are community members during our exploration Canadian; the majority (80 per cent) campaigns in Québec and Ontario. We see are from Québec. this as an important opportunity for First Nations to gain economic benefits from our To further promote diversity within Osisko Mining, projects. Additionally, working with First both our Executive Vice-President of Strategic Nations community members provides a direct Development and the Chair of our Board of communication line to the larger communities, Directors participated in Women Who Rock, as these workers can share information about which aims to connect women to leaders in the Osisko Mining and the way we do business. Cree core cutters at Windfall Lake Project mining industry. Women Who Rock works to Osisko Mining is committed to providing empower women and improve gender diversity in Geology team at Windfall Lake Project opportunities to local First Nations. For example, the industry. at the Windfall Lake camp, Cree First Nation of Waswanipi community members are a key part in the success of the project, filling such positions as environmental assistant, general labourer, core cutter, housekeeper, administrative assistant, Waswanipi community liaison adviser, First Nation human resource facilitator and health and safety prevention officer. Osisko Mining uses the Waswanipi

economic development company, Miyuu Kaa, Miyuu Kaa - Gestion ADC kitchen team at Windfall Lake Project. for civil works, catering and drilling. Several other Cree enterprises also provided goods and Women Who Rock, January 2017: Jose Vizquerra- 2017 Eleonore Regional Project team services at the Windfall Lake Project. Benavides, EVP of Strategic Development and Director At the peak of Windfall Lake and Urban Barry Projects activities, more than 92 First Nation people worked at Osisko Mining’s projects.

Aboriginal Workers 2017 2016 Windfall Lake & Urban Barry Projects >80 12 Garrison Project 6 5 Kan Project 6 4 Total >92 21

9 SUSTAINABLE DEVELOPMENT REPORT 2017 The Osisko Mining team at the annual XPLOR Gala

Awards Osisko Mining won the Québec Mining Exploration Association’s Discovery of the Year award for the Lynx deposit. This discovery, located near the Windfall Lake deposit, changed the exploration strategy around the Windfall Lake Project. The new Lynx deposit has the potential to expand the size of the project and produced a significant ripple effect on exploration activities around the main Windfall Osisko Mining at the Mines and Money Americas 2017 Lake deposit. Osisko Mining also won the 2017 Exploration Award ceremony. Exploration Award North America from Mines and Money Americas. In the coming year, Osisko Mining will focus on infill drilling on the Lynx zone, as well as on the main zones, in order to release a new resource estimate and preliminary economic assessment.

Mandy Gull (Deputy Chief, Cree Nation Government) and John Burzynski (Osisko Mining President and CEO) with 10 SUSTAINABLE DEVELOPMENT REPORT 2017 the 2017 Discovery of the Year award Sustainable development action plan

As part of our sustainable development strategy, Osisko Mining is committed to:

• Evaluating our activities in terms of the potential effects and risks for the natural, human and social environments, with the goal of achieving “zero harm”; • Continuous improvement by monitoring programs, analyzing statistics, conducting audits and establishing plans to improve performance; • Ensuring that employees, subcontractors and suppliers meet our standards of sustainability; and • Ensuring that our board of directors monitors the performance of our sustainability objectives and we provide the resources to reach these objectives.

We monitor our performance in the four key components of sustainability – health and safety, society, environment and economy.

Moose and Caribou Aerial Survey: Windfall Lake Project

11 SUSTAINABLE DEVELOPMENT REPORT 2017 HEALTH AND SAFETY Health and safety

In 2017, Osisko Mining strengthened our Health and Safety (H&S) department by hiring a corporate H&S superintendent and four H&S advisers, two nurses and four security guards for the Windfall Lake Project. We also introduced a new first responder team, mine rescue team and a firefighting team.

An occupational health and safety This table provides our H&S statistics for management system was developed and 2017. We investigate incidents to determine implemented and new policies and procedures underlying causes and establish immediate were introduced to ensure the health, safety action plans to prevent a reoccurrence. and well-being of our workforce. All Osisko Corrective actions are documented and tracked Mining employees, contractors and visitors to ensure completion and closure. attend site H&S orientations. We review and modify our H&S standards regularly to maintain the proper controls.

H&S 2017 STATISTICS Osisko’s employees and contractors Windfall Lake Project All Projects Worked hours 801,546 993,388 First aid incidents 113 131 Medical treatment incidents 20 26 Lost time incidents 7 8 Restricted work incidents 21 22 Lost time injury frequency rate 1.7 1.6 Cumulative frequency rate 7.0 6.0 Total recordable injury frequency rate 11.9 11.27

*Lost Time Injury Frequency Rate *Cumulative Frequency Rate (CFR): *Total Recordable Injury Frequency (LTIFR): (number of lost time ((number of lost time + restricted Rate (TRIFR): ((total medical accidents x 200,000 hours) / (hours work injuries) x 200,000) / (hours aid injuries + restricted work worked year to date) worked year to date) assignments + lost time accidents) x 200,000) / (hours worked year to date)

Underground at Windfall Lake Project

12 SUSTAINABLE DEVELOPMENT REPORT 2017 Action Plan Health and safety (H&S)

Objectives Goals Action Plan 2017-2020 Progress 2016 Progress 2017 • Provide a safe working • Promote a culture • Hire corporate H&S • H&S support system • Occupational H&S department in place (corporate H&S environment. of safety within our superintendent. identified at each site. superintendent, four H&S advisers, two nurses, four workforce. • Finalize occupational H&S • Site-specific H&S manuals security guards). management system. completed. • Developed and implemented an occupational H&S • Continuous improvement management system. of management systems. • Continually updated our standard operating procedures. • Developed and implemented drug and alcohol policy. • Established Windfall Lake Mine Rescue Team (Windfall Lake). • Established fire department and purchased firefighting skid (Windfall Lake). • Established first responder team (Windfall Lake). • Completed risk assessment workshops.

• Ensure our workforce is • Fully trained workforce • Expand Windfall Lake fire • Site safety orientation training • Continued site safety orientation training for all well trained and ready with effective emergency protection equipment and provided to all employees, employees, contractors and visitors. to respond to potential response plan. protocol. contractors and visitors. • Introduced daily H&S meetings emergencies. • Practice emergency drills for • Completed Ontario joint H&S • Updated site-specific emergency plans. identified response teams. committee certification parts • Kept records for H&S employee training (matrix), • Complete needs assessment 1 & 2 (management/worker). including but not limited to first responders training; for H&S training. • On-site risk assessment firefighter training; training on specific equipment • Continue tracking H&S training completed. (Skytrack, boom lift, scissor lift, ATVs). training for all staff. • Site-specific emergency plans • Conducted emergency simulations (Windfall Lake). completed. • Weekly training for first responders (Windfall Lake). • Began record keeping for H&S employee training.

• Monitor, analyze and • Reporting and analyzing • Ongoing reporting of H&S • Six site inspections done. • Collected data for the full year on H&S incidents. audit our safety perfor- incidents. statistics. • Three months of H&S • 2017 lost time incident frequency rate of 1.6. mance. • Audits of on-site practices. information collected in 2016. • More than 250 H&S field inspections. • Analyzed trends and • Lost time frequency rate of 1.5 • Three inspections by CNESST. developed corrective actions in Q4 2016. • Established a risk register by workstation. to reduce incidents. • Improved accident reporting procedure. • Developed and implemented corrective measures process. • Initiated the incident investigation process. • Analyzed incident trends and developed corresponding safety information talks aimed at reducing problem areas or activities. 13 SUSTAINABLE DEVELOPMENT REPORT 2017 2017 main community events

January February March • Visit Waswanipi Community • Waswanipi Mining Exposition • PDAC meetings Osisko Mining • Waswanipi Land Users • Presentation to the • ROM Museum event society Meeting Waswanipi Forestry • Presentation of project • Site Visit: Waswanipi Board Department description and exploration members, CTA and Tallyman update to the federal and Osisko Mining promotes innovation and education. We also provincial governments build relationships with communities by sharing knowledge and April May June maintaining high workforce satisfaction. • Journée Maillage Donneur • Mining Week in • James Bay Cree Communities d’ordre et Fournisseurs Lebel-sur-Quévillon annual information tour organized by Société du Plan • Waswanipi Land Users • Waswanipi Day Nord in Chibougamau meeting • Aboriginal Day at Windfall • Kuujjuaq Mining Workshop • Waswanipi Cree Lake camp • Meeting in Wahgoshig Entrepreneurs meeting • Presentation to Waswanipi Band Council • Introductory Meeting & Project Update – Lac Simon First Nation • Introductory Meeting & Project Update – Obedjiwan First Nation July August September • Meeting in Kuujjuaq • Collaboration agreement • Wahgoshig social event • Meeting with Mayor of with Lebel-sur-Quévillon • Meeting with Tallymen and Lebel-sur-Quévillon and and first meeting of the Waswanipi Natural Resources representative of Society of collaboration committee staff Economic Development • Windfall site visit: MERN • Meeting with Miyuu Kaa • Meeting with the Minister minister, DG of Société (Waswanipi JVs) Osisko Mining’s underground geology team of Innovation, Science and du Plan Nord and Osisko Mining ensures that our activities benefit We continually learn from our host Economic Development Lebel-sur-Quévillon Mayor • Waswanipi land users Aboriginal and local communities by providing communities about Aboriginal culture and meeting employment, identifying business development their relationship to the land. We value their • Windfall Lake site visit for opportunities and participating in cultural knowledge and seek their contribution tallyman and Waswanipi activities. We engage in ongoing dialogue with to minimize the potential effects on the Natural Resources host communities and collect community environment, their cultural heritage and their Department concerns through our consultation activities. traditional activities. Specifically at Windfall October November December In 2017, we held more than 65 meetings in Lake, Osisko Mining regularly met with Cree • First Open House in • First Open House in • Waswanipi Land Users Lebel-sur-Quévillon and Waswanipi and Windfall meeting all regions where we have projects. We send First Nation of Waswanipi representatives and Windfall Lake • Presentation of Windfall Lake • Holiday Party in Waswanipi notification letters to First Nation communities the tallymen, the stewards of traditional Cree • Second collaboration Project to Chibougamau ICM • Presentation of project and municipalities before starting exploration territories, to share information on land use. Committee Meeting in and business people description and exploration activities. The letters include maps and contact Lebel-sur-Quévillon • Meeting with Chibougamau update – Lac Simon First information so local representatives can reach and Chapais Mayors Nation us with suggestions, questions or concerns. • Presentation to CTA General Assembly in Waswanipi • Québec Mines event • Presentation of project description and exploration update – Obedjiwan First 14 SUSTAINABLE DEVELOPMENT REPORT 2017 Nation Action Plan Society

Objectives Goals Action Plan 2017-2020 Progress 2016 Progress 2017 • Design and use technolo- • Promote innovation with- • Continue student • Student internships (two at • Student internships (five) and summer jobs (12). gies that minimize risks to in our workforce. recruitment and provide Windfall Lake, one at Garrison • Participated in lectures and forums. people and the environ- • Grow our workforce and research opportunities for and one at Marban). • Participated in Women Who Rock mining mentorship ment. the knowledge within students. • Participated in university program. Osisko Mining. • Participate in mining lectures and forums. • Researched and selected appropriate water treatment • Share our knowledge and mentorship programs. • Member of PDAC, Québec technology for the Windfall Lake Project. experiences within the • Join the Ontario Mining Mining Exploration mining industry. Association. Association. • Research water treatment technologies. • Build long-term positive • Maintain open • Hire community liaison • Community notification • Sent community notification letters before relationships with our communication with adviser for Windfall Lake. letters sent before initiating initiating exploration (First Nation communities and Aboriginal partners and our Aboriginal and local • Maintain notification system exploration. municipalities). local communities. communities. and grow stakeholder list. • Community meetings held • Community meetings held in all regions where we have • Gain knowledge of • Compile list of key in regions where we have projects (James Bay, Kuujjuaq, Lac Simon, Obedjiwan, community values and community concerns. projects. Waswanipi, Waghoshig). concerns and work to • Attend community events in • Traditional land use study • Sponsored tallymen to QMEA conference. address concerns. each project or region. commenced for Windfall • In-kind donations to tallymen (James Bay and Windfall) • Encourage and promote • Host information sessions at Lake. • First open house in Lebel-sur-Quévillon, Waswanipi and our local and Aboriginal key project milestones. • Agreements in place with Windfall camp (Windfall Lake). workforce. • Participate in Kuujjuaq four Aboriginal communities • Project description video presented to Waswanipi and mining workshop. in Ontario and one in Québec. Lebel-sur-Quévillon communities and our Windfall Lake • Community meetings with • 16 workers from Waswanipi workers. Lac Simon and Obedjiwan and five from Wahgoshig. • Hired Waswanipi community liaison adviser First Nations. • Invited tallymen to QMEA (Windfall Lake). • Identify and support conference. • Prepared and displayed posters to present aspects of programs promoting health, Cree way of life (Windfall Lake). well-being and education in • Field visits: Waswanipi, Lebel-sur-Quévillon and Aboriginal communities. provincial government (Windfall Lake). • Hosted Aboriginal Day (Windfall Lake). • Participated in the Kuujjuaq mining workshop (Kan project). • Attended Waswanipi Day (Windfall Lake). • Presented infomation at Plan Nord event, Journée donneurs d’ordres et fournisseurs in Chibougamau. • Participated in Mining Week in Lebel-sur-Quévillon: presented to public, met local entrepreneurs and held an information booth in the mall (Windfall Lake). • Aboriginal employment through local contractors: • Six Inuit workers on Kan Project • More than 92 workers from Cree First Nations communities (mainly Waswanipi) on Windfall Lake and Urban Barry Projects 15 SUSTAINABLE DEVELOPMENT REPORT 2017 • Six workers from Wahgoshig at Garrison Project • Maintained records of community concerns. Action Plan Society

Objectives Goals Action Plan 2017-2020 Progress 2016 Progress 2017 • Maintain positive labour • Engage with our • Undertake annual • Above-average compensation • Completed annual performance reviews. relations and high employees to understand performance reviews. compared to our industry. • Established salary scale according to employment workforce satisfaction. their values. • Track pay rates by • Benefits to protect categories. • Promote diversity employment category and employees and their families. and equity within our gender. • Long and short term workforce. • Measure workforce turnover. incentive programs. • Track workforce training by hours/year and gender.

Core, Windfall Lake Project

16 SUSTAINABLE DEVELOPMENT REPORT 2017 BUILDING RELATIONSHIPS

Aboriginal Day Relationship with celebration at Aboriginal communities Windfall Lake

Sharing information and transparency

Cree First Nation of Waswanipi Throughout 2017, Osisko Mining shared fish inventory, and will be part of the moose information about the Windfall Lake Project and caribou inventory next winter. We also with the Cree First Nation of Waswanipi held meetings in the community regarding through letters, meetings and presentations traditional knowledge and land use. to the band council and general assemblies. Each year, to help the communities better This included more than 25 different meetings understand the implications of exploration and with Waswanipi representatives, tallymen, to help create a network of industry contacts, entrepreneurs and community members. we sponsor community members to join us at These meetings were an opportunity to the Québec Mineral Exploration Association explain the work planned and to listen to (QMEA) Conference in Montreal. Among them the community. The main concerns regarded were two tallymen related to our Windfall Lake employment and contract opportunities, and Project and representatives from the Chisasibi protection of the environment and human and Wemindji communities. We also met beings. with Cree human resource development and Osisko Mining hired several people from the Waswanipi representatives during the PDAC Waswanipi community in 2017 and shared event in March, and organized field visits to information about our exploration activities, the Windfall Lake Project in the winter and environmental baseline data collection, the summer. The tallyman, his family, band office environmental assessment process and the staff, band council members and Cree Trappers’ Windfall Lake Project description. The tallyman Association representatives visited the camp, participated in some of the baseline data exploration ramp infrastructure and a drill rig. collection for the project, such as the

Image Caption here

Waswanipi underground tour at Windfall Lake: Chief, Deputy Chief, tallyman and other community members

17 SUSTAINABLE DEVELOPMENT REPORT 2017 ABORIGINAL COMMUNITY

Other Aboriginal communities

Wahgoshig Kuujjuaq Wahgoshig First Nation is an Algonquin The Osisko Mining team met with Nunavik community located in Ontario, located a few representatives to address concerns about kilometres from the Garrison Project. In 2017, our Kan Project, located approximately 90 Osisko Mining met with Wahgoshig community kilometres from the village of Kuujjuaq. members to introduce our company and to Our meetings included discussions with provide an update on exploration activities. representatives from the Nayumivik We also visited the community and met Landholding Corp., the Nunavik Mineral with Wahgoshig Resources Inc. personnel. Exploration Fund, the Makivik Corp. and the

Garrison Project managers attended a social mayor of Kuujjuaq. Kan Project, Kuujjaq event organized by Wahgoshig First Nation, The main concerns expressed by people from reinforcing the relationship between mining Kuujjuaq were minimizing environmental companies and Wahgoshig First Nation. Six impacts and maximizing economic benefits Wahgoshig First Nation community members to the community. The team explained the worked on the Garrison Project in 2017 and environmental protection measures in place numerous Wahgoshig contractors were used for and shared a list of Inuit contractors who activities related to the drill program. work on the project. Routinely including Inuit contractors in our tendering process is an important aspect of our sustainable

development strategy. During the summer of Tour of James Bay Cree communities 2017, six Inuit people worked on the project. We also use the services of local entrepreneurs such as Air Inuit, First Air, Tivi, Avataa Explorations and Logistics, Avataa-Rouillier Drilling and others. After the field season, all excess food was donated to the community, along with seven oil stoves that have been replaced by electric heaters in the camps. These will be used by land users for heating in the hunting

emergency shelters. Meeting with Lac Simon First Nation Osisko Mining presented the Kan Project at the Kuujjuaq Mining Workshop in April, met with the local representatives at the Prospectors and Developers Association of Canada (PDAC) event in Toronto, in Kuujuuaq during the summer and at the XPLOR convention in Montreal in the fall.

First Nations of Lac Simon and Obedjiwan Nation and the Lac Simon community of the Garrison workers including three workers from Wahgoshig First Nation In addition to Waswanipi Cree First Nation, two Anishinabeg Nation. Osisko Mining met with other communities have expressed a potential each of these communities twice in 2017 to interest in the Windfall Lake Project. They share information about exploration activities 18 SUSTAINABLE DEVELOPMENT REPORT 2017 are Obedjiwan community of the Atkamekw and the details of the Windfall Lake Project. LOCAL COMMUNITY Relationship with Sharing knowledge, local communities training and innovation

Lebel-sur-Quévillon Lebel-sur-Quévillon is the nearest non-Aboriginal office for a workforce of approximately 20 Workforce training and the expertise of our community to the Windfall Lake Project. workers in the city. Osisko Mining holds a seat employees anchor Osisko Mining’s success. The Osisko Mining team met its Mayor and on the board of the Société de développement We encourage our employees to pursue management team to provide an update on the économique de Lebel-sur-Quévillon and entrepreneurial, technical, geological, and project, share information about employment, supports community initiatives through our health and safety training. Osisko Mining also goods and services requirements and learn donation and sponsorship program. requires health and safety training, such as risk about the city. In August, Osisko Mining and the assessment, first aid, safe operating procedures city of Lebel-sur-Quévillon signed an agreement Chapais-Chibougamau and emergency preparedness. to maximize socio-economic benefits to the Osisko Mining presented the Windfall Lake Osisko Mining invests in innovation community. Osisko also hosted a site visit for the Project and the company at two events through lectures in geology, mining and Québec minister of natural resources (MERN), in Chibougamau — the Journée donneurs entrepreneurship. In 2017, we provided paid the president and general director of Société du d’ordres et fournisseurs organized by Société internships to five students and 12 summer jobs Plan Nord and the mayor of Lebel-sur-Quévillon. du Plan Nord and an evening organized by the for students pursuing careers in the mining Osisko participated in the Mining Week Canadian Mining Institute and Développement industry. In 2017, Osisko Mining provided organized by the Société de développement Chibougamau. financial support for school activities promoting économique de Lebel-sur-Quévillon. Our Vice- The Osisko Mining team met with the mayors science and education and supporting research. President exploration Québec presented the of Chibougamau and Chapais to introduce projects and the company to the public, and the Windfall Lake Project and the regional Osisko Mining meet with local entrepreneurs exploration projects. The mayors were interested and staffed an information booth. in opportunities for their local businesses and Osisko Mining is committed to community contractors. involvement, as shown by the opening of an

The collaboration committee’s first meeting in August Fire fighting training at Windfall Lake Project

19 SUSTAINABLE DEVELOPMENT REPORT 2017 Environment

Our goal is to minimize our environmental footprint by using efficient techniques, conserving resources and using progressive rehabilitation at our exploration sites. A rehabilitation program underway includes the restoration of drill pads and lake breakthroughs by grading the surface to re-establish water flow and putting the organic layer back in place. Osisko Mining aims to minimize possible effects on land, water, air, flora and fauna. All spills and non-compliance issues are reported to management and the board of directors. Progressive reclamation of our exploration activities includes routine cleaning and restoration of drill pads, mechanical trenches, camp sites and other areas. Drill pads are reclaimed in two stages. In the first stage, all equipment, garbage and fuel is removed from the drill site. The drill casing has been properly cut and flagged, sumps are backfilled and the drill pad area is levelled. In the second stage, once confirmation that drill pad will not be required for additional future drilling, inspection will take place to assess regrowth of vegetation. If deemed necessary, vegetation assistance (i.e. seeding) will be done.

Project Area disturned Area remediated - drill pads (m2) (1st stage) - drill pads (m2) Windfall Lake Project 270,000 50,000 Garrison Project 85,248 68,198

When choosing areas for future infrastructure, we aim to minimize our impacts by utilizing areas previously disturbed by historical exploration or forestry activities.

Windfall Lake Project

20 SUSTAINABLE DEVELOPMENT REPORT 2017 ENVIRONMENT

Water management Mine water and runoff water Prior to dewatering the existing exploration new unit will reduce the concentration to an ramp, the ramp water quality was assessed acceptable level. and a suitable water treatment system was We use recycled water to operate our developed using the existing basins and ditches. underground equipment. A water cleaning After cleaning and repairing the infrastructure, system that removes suspended solids will be new water treatment units, ¬including a installed underground for operation in 2018. Geotube® platform and water treatment modules, were installed. Dewatering of the Potable water and domestic water exploration ramp took place in July and August. The Windfall Lake camp facilities were expanded In total, 71,144 m3 of water was treated at the in 2017 to allow for 300 workers to stay at the Windfall Lake Project in 2017. Of that, 36,536 m3 site. All the relevant infrastructure was updated, was during the initial ramp dewatering process. including septic fields and drinking water wells. Ongoing mine water and runoff water from the Three artesian wells providing potable water stockpile is directed to the water treatment and three septic installations handle the needs system to ensure the effluent meets regulations. of the camp. Water quality is monitored weekly In 2017, all effluent sample results were to ensure compliance. In 2017, we found two Windfall Lake Project environmental emergency compliant with the legislation. non-conformities. Warning signs were quickly Spill management A preventive treatment system to reduce the installed, disinfection completed and the Spill Management 2017 Spills less Spills greater Osisko Mining’s spill management plan strives Project than 20L than 20L concentration of ammonia nitrogen will be situation returned to normal within a couple of to minimize the potential effects of any spill. Windfall 73 5 installed during the summer of 2018. If the days. For the rest of the year, all water analyses The plan ensures that all spills are managed Urban Barry 0 0 toxicity caused by ammonia nitrogen is no complied with the legislation. promptly and with care. Québec regulations Quévillon 0 0 longer controllable with pH adjustment, the require reporting all spills as soon as possible, Garrison 1 0 and federal legislation requires reporting all spills that reach or will likely reach water. The Windfall Lake camp has an environmental Our plan emphasizes spill avoidance, and all emergency unit containing the material to employees and contractors are aware of the clean spills, and additional spill kits are available spill reporting and cleaning procedures. Spill around the site. When necessary, Osisko Mining kits are available on each exploration project uses a vacuum unit to recover contaminated and employees have been trained in proper water and solids. Sealed containers are available spill cleanup. There were 79 spills in 2017. All to store contaminated soils until they can be were reported as required and affected areas disposed of at an authorized disposal site. remediated. The environmental team performs regular inspections at the camp site, ramp sector, drill rigs and drilling contractor’s garage to proactively identify and correct any potential impacts.

Windfall Lake Project’s new septic field

21 SUSTAINABLE DEVELOPMENT REPORT 2017 ENVIRONMENT

Waste management Domestic waste First step of the environmental assessment Containers segregate residual materials: domestic Osisko Mining has filed the Windfall Lake Project waste, metal, cardboard and construction waste. description report with the federal government A contractor transports residual materials from and the preliminary project information report Windfall Lake to authorized locations. Metal is with the Québec government. This is the first recovered for recycling by a company from Amos, step in the environmental assessment process. Québec. We received guidelines from both governments A composter will be commissioned in the and continue to gather environmental data for summer of 2018 to reduce the impact on landfill the baseline study supporting the environmental and transportation by at least 50 per cent. Kitchen assessment. waste and cardboard will create compost for use in restoring the drilling sites. Environmental baseline data collection Supporting the environmental assessment, Osisko Hazardous materials Mining undertook many field visits to collect Osisko Mining tightly manages residual hazardous baseline data. On the Windfall Lake Project, materials. We supervise contractors so they we collected data about surface water and manage their residual hazardous materials sediments, noise, vegetation, fish and aquatic according to regulations and regularly inspect habitat, terrestrial fauna, geochemistry and storage sites, both ours and those of the hydrogeology. The tallyman was involved in the contractors. Procedures are in place to store, fishing inventory. He will also be part of a moose label, segregate and properly dispose of residual and caribou inventory in 2018. hazardous materials through authorized firms. A dome was built at the Windfall Lake Project site for residual hazardous materials storage and for a treatment system for oily water. The concrete floor is scheduled to be poured in late spring 2018.

Restoration plan updated As required by the Québec government, we submitted an updated closure plan for the Windfall Lake Project in July 2017 and expect approval in the middle of 2018. A restoration plan was also filed for the Garrison Gold Pike Project.

Learning about the environment Osisko Mining undertook several environmental studies in 2016, including project-focused studies Windfall Lake Project’s camp capacity is permitted to allow and external research initiatives. These studies 300 workers increased in intensity in 2017.

22 SUSTAINABLE DEVELOPMENT REPORT 2017 Action Plan Environment

Objectives Goals Action Plan 2017-2020 Progress 2016 Progress 2017 • Evaluate the potential • Understand the potential • Complete Environmental • Environmental baseline • Hired environmental site supervisors (Windfall Lake). effects of our projects and effects of our planned Impact Assessments and data collection underway at • Filed project description and preliminary project activities. activities and identify share findings with our Windfall Lake and Marban. information and received guidelines for environmental mitigation measures. board, Aboriginal partners • Monitor water quality at impact assessments (Windfall Lake). and stakeholders. Windfall Lake and Garrison. • Collected environmental baseline data (Windfall Lake) • Identify potential mitigation • Invest in collaborative Caribou • Geochemical characterization of ore, tailings and waste and/or compensation Ungava research project. rock (Windfall Lake). measures. • Support Association • Met with provincial and federal leads for the Forestière des deux rives environmental assessment (Windfall Lake). (2016-2018). • Monitored water quality at Windfall Lake and Garrison. • Supported Association Forestière des deux rives (2016-2018) and Caribou Ungava research project.

• Conserve our use of water • Understand the water • Initiate GHG emissions • Initial environmental baseline • Continued environmental baseline information and and energy. and energy use for our estimate for Windfall Lake information and mapping mapping. projects and identify Project. done. • Measured and reported water use (Windfall Lake). conservation and • Measure water use and • Identified water sources and discharge points management measures. report by project (for major (Windfall Lake) projects). • Identify water sources and discharge points.

• Minimize our land • Land use management • Measure solid waste shipped • Environmental management • Measured solid waste shipped to landfill (Windfall Lake). disturbance, waste practices that respect to landfill. plans in place by drilling • Tracked hazardous waste disposal (Windfall Lake). generation and emissions, riparian areas and include • Track hazardous waste contractors. • Began development of a recycling program and rehabilitate any ongoing rehabilitation disposal. • Planned exploration activities (Windfall Lake). disturbances. efforts. • Develop recycling program. incorporating setbacks near • Updated closure plan (Windfall Lake). • Solid waste management • Track areas of land water. • Restored exploration ramp water treatment program that diverts disturbances and • Introduced spill management infrastructure (Windfall Lake). recyclable and reusable remediation. plan. • Prepared rehabilitation and monitoring plan (Gold Pike). materials. • Update Windfall Lake • Cleaned four reportable spills • Reported and cleaned all spills • Spill management restoration plan. in 2016. measures that reduce • Develop remediation plan for • Erosion and sediment control incidents and overall Gold Pike Project. at Windfall Lake, Garrison and effects of spills. Marban.

23 SUSTAINABLE DEVELOPMENT REPORT 2017 ECONOMY Economy

Creating wealth Osisko is a publicly traded company, with shares on the Toronto Stock Exchange (OSK.TO). Osisko continues to be well financed, with approximately $190 million in cash and investments as of December 31, 2017. Major shareholders include:

• Osisko Gold Royalties Ltd. • Management and directors • M&G/Vanguard • Blackrock • J.P. Morgan Asset Management UK • Tocqueville

In 2017, Osisko Mining spent more than $121 million on exploration and evaluation assets, mostly on the Windfall Lake and Urban Barry Projects, and $11 million on general and administration expenses, salaries and benefits.

I’M GOING TO NEED ALL THESE LOGO FILES TO RECREATE THIS GRAPHIC (OR PROVIDE HIGH RES FILE)

Core, prepared for storage in core library at Windfall Lake Project

24 SUSTAINABLE DEVELOPMENT REPORT 2017 Contributing to Our Communities

Osisko Mining is committed to sharing wealth with our communities by: • Identifying and establishing a relationship with stakeholders with an interest in our activities • Contributing to the development of our host communities through community-focused sustainability projects • Building long-term relationships with Aboriginal communities with an interest in our projects

In 2017, Osisko Mining developed sponsorship and donation guidelines, focusing on support for: • Innovation, technology and science • Training future generations of workers and leaders • Environmental protection and development of best practices • The economic vitality and quality of life of the regions where we operate, our host communities and their community and cultural activities • Promoting healthy habits in our host communities • Improving public awareness about the mining industry

In celebration of Canada 150, Osisko Mining sponsored the Avro Arrow Recovery program

25 SUSTAINABLE DEVELOPMENT REPORT 2017 Action Plan Economy

Objectives Goals Action Plan 2017-2020 Progress 2016 Progress 2017 • Create jobs and promote • A growing workforce with • Track workforce by • $1.6M in employee taxes • $6M in employee taxes and $1.3M in payments to economic development. full-time employment employment category, and $0.4M in payments to government. and benefits. gender and whether they are government. • Set up and reported workforce by employment category, a full- or part-time employee. gender and whether they are a full- or part-time employees.

• Favour local purchases • Thriving local • Provide targeted • 89% of purchases in Québec • 81% of purchases in Québec and Ontario. and contracts. communities that benefit opportunities for local and and Ontario. • $23M in contracts and purchases from Aboriginal from our activities and Aboriginal businesses. • $0.3M in contracts and businesses. support our projects. • Participate in mining purchases from Aboriginal • Participated in mining expositions and conferences. expositions and conferences. businesses. • Established a collaboration committee with • Register on Société du Plan Lebel-sur-Quévillon. Nord business platform. • Track contracts and purchases by region. • Work with communities to develop a business registry.

• Share the wealth with our • Long-term benefits • Identify key areas for • Sponsored PDAC’s student • Developed guidelines for sponsorships and donations. communities. to local communities sponsorships and donations. industry mineral exploration • Various sponsorship and donations to local through regional • Develop guidelines for program. organizations. prosperity and social sponsorships and donations. • Donation to Malartic’s Festival • Corporate sponsorship and donations. development. • Monitor projects over time to Western. measure social benefits. • Participant in the Goodman Gold Challenge.

26 SUSTAINABLE DEVELOPMENT REPORT 2017 Contact Us

Osisko Mining Inc.

Head Office 155 University Avenue 1440 Toronto, Ont., M5H 3B7

Phone: (416) 848-9504 Fax: (416) 363-9813 E-mail: [email protected] TSX : OSK

Social Media Web site: www.osiskomining.com Facebook: @MiningOsisko Twitter: @Osisko_Mining Instagram: @Osisko_Mining

Underground geology team at Windfall Lake Project

27 SUSTAINABLE DEVELOPMENT REPORT 2017