Primero Mining : Reports 2015 Year-End Mineral Reserves and Resources;Increases Total Mineral Resources and Announces Additional Exploration Results From the Black Fox Froome Zone

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PRIMERO REPORTS 2015 YEAR-END MINERAL RESERVES AND RESOURCES; INCREASES TOTAL MINERAL RESOURCES AND ANNOUNCES ADDITIONAL EXPLORATION RESULTS FROM THE BLACK FOX FROOME ZONE‌

(Please note that all dollar amounts in this news release are expressed in U.S. dollars unless otherwise indicated.)

Toronto, Ontario, March 16, 2016 --- Primero Mining Corp. (''Primero'' or the ''Company'') (TSX:P, NYSE:PPP) today announced its 2015 year-end Mineral Reserves and Mineral Resources, as well as recent exploration results from the newly discovered Froome Zone at its Black Fox mine located near Timmins, Ontario, Canada.

Highlights:

• Mineral Resources Increased Beyond Depletion: Primero successfully increased total Mineral Resources across its assets, with total Measured and Indicated Mineral Resources of 3.1 million ounces of gold plus 88.3 million ounces of silver in addition to total Inferred Mineral Resources of 1.2 million ounces of gold and 77.1 million ounces of silver.

• Reserve Estimation to Maximize Free Cash Flow: Primero successfully replaced mined depletion at both of its operating mines from its 2015 drilling results but has elected to implement improved reserve estimation methodologies to maximize free cash flow generation and ensure future profitability. An increased cut-off grade has been applied to Black Fox Mineral Reserves to account for expected operating expenditures and required sustaining costs which led to the removal of marginal, high all-in cost ounces. San Dimas materially replaced Proven and Probable Mineral Reserves in 2015, despite mining depletion and the removal of un-mineable high-grade pillars. Primero's year-end 2015 total Mineral Reserves have remained in line with year-end 2014 on a total tonnage basis. Contained gold ounces declined from 1.9 million ounces in 2014 to 1.8 million ounces in 2015, while contained silver increased from 65.8 million ounces in 2014 to 70.5 million ounces in 2015.

• Initial Resource at Black Fox Froome Zone: Primero has outlined an initial Mineral Resource estimate for the highly prospective Froome Zone located approximately 800 metres west of the Black Fox mine. The initial estimate only includes drilling up to February 17, 2016 and contains Indicated Mineral Resources of 43,000 ounces of gold plus Inferred Mineral Resources of 129,000 ounces of gold.

  
  

• Primero Remains Confident Froome Zone Will Continue to Grow: Primero's exploration team continues to delineate and expand the Froome Zone, demonstrating high potential for further growth. Highlights from recent drilling, excluded from the initial resource calculation, include 4.8 grams per tonne ("g/t") gold over 46.0 metres true width (16PR-G065), 4.7 g/t gold over 45.9 metres true width (16PR-G066), and 8.6 g/t gold over 24.2 metres true width (16PR-G072).

''Our investment in exploration continues to pay off.'' stated Ernest Mast, President and Chief Executive Officer. ''We have successfully grown our total Mineral Resources through the addition of new mineralized areas, such as the Froome Zone at Black Fox. We have taken measures to improve our modelling methodologies to maximize future free cash flow generation and provide more certainty to our mine plans. Looking to the future, we have a very positive outlook with expected exploration results from the Froome Zone and other Froome-like targets at Black Fox, and from areas located outside the Silver Purchase Agreement at San Dimas such as the Ventanas property and Lechuguilla concession.''

Mineral Reserves and Mineral Resources

The Company completed its 2015 year-end Mineral Resource and Mineral Reserve estimation for San Dimas, Black Fox, and Black Fox Froome Zone internally. Through its 2015 exploration drilling, Primero added 241,000 ounces of gold into Proven and Probable Mineral Reserves at a cost of approximately $105 per ounce, more than replacing 2015 mining depletion of 229,000 ounces of gold. However, a reduction of 177,000 ounces of gold was attributed to more conservative block model capping and estimation parameter adjustments.

On a Measured and Indicated Mineral Resource basis, the Company added approximately 444,000 ounces of gold through its 2015 exploration drilling at a finding cost of approximately $57 per ounce, well ahead of Measured and Indicated Resource depletion of 252,000 ounces of gold. Block model and estimation parameter adjustments reduced the estimate by approximately 227,000 ounces.

The Company used metal prices of $1,200 per troy ounce of gold and $18.00 per ounce of silver and a foreign exchange ratio of 15.50 Mexican Pesos per US$1.00 for its San Dimas mine Mineral Reserve and Mineral Resource estimations. The Company has implemented a more stringent approach to reserve modelling at San Dimas that included the removal of high grade pillars and newly identified voids and ''halos'' from the mine plan. Based on the low-cost production achieved in 2015, and further efficiencies expected to be achieved with the completion of the 3,000 tonnes per day mill expansion expected in Q3 2016, some veins with lower-grade mineralization have been added into the Mineral Reserves, contributing to the reduction in the overall Mineral Reserve grade. It is important to note that the positive exploration results included in Primero's news release dated February 29, 2016 are not included in the year-end 2015 Mineral Reserve and Resource estimation detailed below. That is, the newly discovered Convención vein, the high-grade Regina vein, and the extension of the Victoria vein have been excluded from the year-end 2015 estimation.

The Company's San Dimas Mineral Reserves and associated Mineral Resources were estimated using GEMS software with ordinary kriging interpolation applied to major veins and inverse distance squared interpolation applied to minor veins. The remaining veins outside of Mineral Reserves and their associated Mineral Resources were estimated using a polygonal method and included in Inferred Resources. The Mineral Reserves and associated Mineral Resources were constrained in 61 individual geological models (57 individual geological models in 2014). Leapfrog vein designs were modelled along the vein contacts, and were defined by gold and silver grades, structural geology, quartz veining and mineral alteration. Grade estimation was performed on 3 metre long by 3 metre high by 0.5 metre wide blocks. Variable grade capping was applied to

veins supported by statistical analysis and visual checks. To convert Mineral Resources to Mineral Reserves, mining dilution was added and mining recovery factors were applied on an individual vein basis and respecting mining methodology. For the block-modelled veins, Measured and Indicated Mineral Resources were defined by combining several criteria such as a minimum of four drill holes within 15 metres and 30 metres respectively, whereas Inferred Mineral Resources were estimated with a minimum of 2 drill holes within 30 to 45 metres. The Company continues to utilize an external laboratory for all drill samples at San Dimas.

The Company did not receive sufficient additional information in 2015 to provide an update on the Ventanas Mineral Resources. Exploration of this property was re-activated in 2015 and the Company plans on more aggressively explore the Ventanas high-grade veins in 2016 with a $4 million budget and an updated Mineral Resource estimation at year-end 2016.

The Company used a gold price of $1,200 per troy ounce and a foreign exchange ratio of CAD$1.25 per US$1.00 at its Black Fox mine. Additionally the Company adopted a more-conservative approach to cut-off grade determination to maximize future free cash flow generation. The Mineral Reserve cut-off was determined using expected operating expenses plus sustaining costs, and resulted in an increased underground Mineral Reserves cut-off grade from 3.70 g/t to 4.44 g/t.

The Company's Black Fox Mineral Reserves and Mineral Resources were estimated using a block modelling approach with inverse distance squared interpolation. Grade estimation was performed on 3 metre long by 3 metre high by 3 metre wide blocks. High-grade capping was reduced from 200 g/t in 2014 to 80 g/t in 2015 as supported by statistical analysis. Indicated Mineral Resources were defined by combining several criteria such as a minimum of 2 drill holes with the closest being within 20 metres. To convert Mineral Resources to Mineral Reserves, a minimum mining shape size of 500 tonnes was considered. External mining dilution and mining recovery factors were applied to individual mining areas, as was consideration for operating and sustaining costs based on past production data. Crown pillar Mineral Reserves were added/removed based on an individual evaluation of each area on the basis of economic recoverability.

For the Froome Zone, Mineral Resources were estimated using a block modelling approach with inverse distance squared interpolation. Grade estimation was performed on 3 metre long by 3 metre high by 3 metre wide blocks and a bulk density of 2.7 tonnes/m3. Reported Mineral Resources are uncapped as dataset was determined to have a low-sensitivity to grade capping due to the disseminated nature of the ore body. Indicated Mineral Resources were defined by combining several criteria such as a minimum of three drill holes within 30 metres.

Despite positive results received from infill drilling completed in the first-half of 2015, the Grey Fox project became a lower-priority target for exploration in 2015 following the discovery of the Froome zone at Black Fox. As previously disclosed, expenditures at Grey Fox have been minimized in 2016, but the Company may look to re-evaluate the project should gold prices sustain current levels.

Table 1: Total Mineral Reserves and Mineral Resources as at December 31, 2015

Classification	Property	Tonnage (Mt)	Gold Grade (g/t)	Silver Grade (g/t)	Contained Gold (koz)	Contained Silver (koz)
Mineral Reserves
Proven & Probable	San Dimas	5.2	4.8	329	809	55,193
Proven & Probable	Black Fox	2.1	3.6	237
Proven & Probable	Cerro	32.2	0.7	15	712	15,335
Total Proven & Probable	1,758	70,528
Mineral Resources
Measured & Indicated	San Dimas	5.1	6.0	409	971	66,540
Measured & Indicated	Black Fox	3.1	5.2	521
Measured & Indicated	Grey Fox	4.7	4.4	668
Measured & Indicated	Cerro	47.9	0.6	13	923	20,546
Measured & Indicated	Ventanas	0.2	2.5	258	12	1,286
Total Measured & Indicated	3,095	88,372
Inferred Resources	San Dimas	7.0	3.6	330	801	74,030
Inferred Resources	Black Fox	1.0	5.9	188
Inferred Resources	Grey Fox	1.3	4.2	174
Inferred Resources	Ventanas	0.2	2.3	412	17	3,039
Total Inferred Resources	1,180	77,069

Notes to Mineral Reserve Statement:

1. Assumed gold price of US$1,200 per troy ounce and silver price of US$18 per troy ounce.

2. San Dimas cut-off grade of 2.50 g/t AuEq based on total operating cost of US$96.57/t. Metal supply contract obligations have been referenced in determining overall vein reserve estimate viability. Black Fox underground cut-off grade of 4.44 g/t gold based on total all-in costs of C$194.00/t (C$135/t direct costs and C$59/t sustaining capital).

3. Assumed processing recovery factors at San Dimas for gold of 97% and silver of 95% and 95% for gold at Black Fox.

4. Exchange rate assumed is 15.50 Mexican pesos/US$1.00 and CDN$1.25/US$1.00.

5. The Mineral Reserve estimates for San Dimas Mine set out in the table above have been reviewed and approved by Mr. Clifford Lafleur, P.Eng., Director of Technical Services, Primero and Mr. Patrick McCann, P.Eng., Principal Engineer, Primero and a QP for the purposes of National Instrument 43-101 ("NI 43-101"). The Mineral Reserve estimates for Black Fox Mine set out in the table above have been reviewed and approved by Mr. Clifford Lafleur, P.Eng., Director of Technical Services, Primero and Mr. Russell Pennell, P.Eng., Senior Mine Planner, Primero and a Qualified Person ("QP") for the purposes of NI 43-101.

6. Figures may not add due to rounding.

Notes to Mineral Resource Statement:

1. Mineral Resources are total and include those resources converted to Mineral Reserves except Cerro del Gallo Mineral Resources which are calculated exclusive of Mineral Reserves.

2. Assumed gold price of US$1,200 per troy ounce and silver price of US$18 per troy ounce.

3. San Dimas cut-off grade of 2.0 g/t AuEq was applied. Black Fox open-pit cut-off grade of 0.9 g/t gold and underground cut-off grade of 3.4 g/t were applied. Grey Fox open-pit cut-off grade of 0.9 g/t gold and underground cut-off grade of 3.0 g/t were applied.

4. At San Dimas a constant bulk density of 2.6 tonnes/m3 has been used. At Black Fox a constant bulk density of 2.84 tonnes/m3

has been used.