Castle Mountain Reports Phase 3 Drill Results

- including 9.22 g/t gold over 30.5 metres and 2.43 g/t gold over 123.4 metres -

TORONTO, ONTARIO – June 1, 2015 – Castle Mountain Mining Company Limited ("Castle Mountain" or the "Company" – TSX VENTURE: CMM; OTCQX: CTMQF) is pleased to report assay results from the Company’s Phase 3 drill campaign completed during Q1-2015 at the Castle Mountain Gold Project (the “Project”) in SE California, USA.

The 10-hole program, totaling 3,792 metres of combined Reverse Circulation (“RC”) and Core drilling, was a follow-up to encouraging assay results returned during the 2014 Phase 2 drill campaign which targeted gaps and extensions related to the known mineral resources on the property. Phase 3 drilling in the central portion of the resource area successfully encountered additional gold mineralization in the Lucky John and North Lucky John areas. For a location map of recent drill holes, please click this link:

http://www.castlemountainmining.com/Investors%20Library/2015-Drill-Map.pdf

Assay highlights from the Phase 3 program include:

• 9.22 g/t gold (“Au”) over 30.5 metres, including
• 15.14 g/t Au over 18.3 metres in hole CMM-073 (Lucky John)

2.43 g/t Au over 123.4 metres, including

23.25 g/t Au over 6.1 metres in hole CMM-071 (Lucky John)

1.27 g/t Au over 67.7 metres, including

2.86 g/t Au over 20.4 metres in hole CMM-070 (Lucky John)

1.26 g/t Au over 62.8 metres, including

32.90 g/t Au over 1.50 metres in hole CMM-068 (Lucky John)

1.55 g/t Au over 66.1 metres, including

17.48 g/t Au over 2.90 metres in hole CMM-074 (North Lucky John)

President and CEO, David Adamson commented “These latest results confirm that the mineralizing system continues to display a significant high grade component. They build on the impressive results of the previous 37 holes, all of which have been completed since the most recent resource update in late 20131. They also clearly demonstrate that the limits of the gold mineralized system on the property remain unknown and extend beyond the scope of the previous resource estimate.”

Lucky John Target

Seven holes totaling 3,228 metres were drilled to follow-up on the results from RC hole CMM-060 drilled in 2014, which returned 74.4 metres of 9.11 g/t, including 35.1 metres of 18.97 g/t2, immediately southwest of the JSLA backfilled pit. Two holes, CMM-068 and 077, were designed as near core twins of CMM-060 but deviated off course and failed to return comparable grades. The five remaining holes were drilled as step-outs at a minimum distance of 30 metres, with the most encouraging intercept returned in CMM-073, located 60 metres north of CMM-060. This hole returned 9.22 g/t Au over 30.5 metres, including 15.14 g/t Au over 18.3 metres. The mineralization at Lucky John remains open in all directions and may be related to the NE trending, sub-vertical structural fabric.

Assay highlights are summarized in the table below.

2015 Assay Highlights – Lucky John Target

* Interval represents cored length – not true thickness.

All new holes at the Lucky John target were drilled at 059 to 259 degrees azimuth, with dips of -70 to -81 degrees, and to an average depth of 475 to 500 metres. True widths are estimated to be 60-90% of the intersected widths.

North Lucky John Target (165 metres north of Lucky John)

Three holes totaling 564 metres were drilled to follow-up on the results in RC hole CMM-054 which returned 30.31 g/t Au over 33.3 metres, including 94.04 g/t Au over 10.6 metres2, along the southern margin of the proposed JSLA pit outline. Two holes, CMM-075 and 076 were drilled 30 metres to the southwest and northeast respectively. A third hole, CMM-074, was drilled perpendicular to CMM-054 to aid in determining the orientation of the mineralized intercept. CMM-074 returned 1.50 g/t Au over 66.10 metres, including 17.48 g/t Au over 2.90 metres. While the high grade intercept in CMM-054 appears to be relatively restricted in extent, broad zones of gold mineralization were returned which remain open for follow-up to the west, southwest, south, and at depth.

Assay highlights are summarized in the table below.

2015 Assay Highlights – North Lucky John Target

* Interval represents cored length – not true thickness.

** Intervals are in JSLA backfill material and not bedrock

All new holes at the North Lucky John were drilled at 142 or 322 degrees azimuth, with dips of -66 to -75 degrees, and to an average depth of 180 to 200 metres. True widths are estimated to be 60-90% of the intersected widths.

Future Exploration Targeting

A thorough data review is currently underway to update the existing 3D geological and structural model. An onsite structural field study, in conjunction with petrographic work, is also slated for early June in order to determine the timing and controls on gold mineralization to aid future targeting. Gold mineralization is presently interpreted as wide-spread disseminations, and as higher grade, discrete shallowly-dipping and/or sub-vertical zones.

Overall 47 combined core and RC holes totaling 13,927 metres have been drilled on the Project since the last resource update1, and have targeted poorly-drilled areas within, adjacent, and below current pit shells. For a tabulation of assay highlights for all 47 drill holes completed since the 2013 resource, please click on this link: http://www.castlemountainmining.com/Investors%20Library/2015-CMM-47-Hole-Assay-Highlights.pdf

“We already see clear opportunities to expand the defined limits of what is a very large gold mineralizing system. Our goal is to develop new targets with potential to add near-term and low strip ratio ounces adjacent to, and on trend of the existing gold mineral resources.” stated Ian Cunningham-Dunlop, VP Exploration.

There are several high priority target areas which are interpreted to have significant potential for additional gold mineralization, many of which have the additional benefit of lowering the overall strip ratio of the Project. For a general outline of target areas, please click on this link:

http://www.castlemountainmining.com/Investors%20Library/2015-Target-Area-Map.pdf

To review a set of property-wide drill cross-sections highlighting gold distribution, please click on this link:

http://www.castlemountainmining.com/Investors%20Library/2015-Cross-Sections.pdf

Ian Cunningham-Dunlop, P. Eng., is the Company’s Vice President - Exploration and designated Qualified Person for this news release within the meaning of NI 43-101 and has reviewed and verified that the technical information contained in this release is accurate and approves of the written disclosure of same.

All gold assays are by a 30 g Fire Assay charge followed by an atomic absorption finish (with a 0.0005 g/t lower reporting limit). Cyanide solubility assays are determined by agitating the sample in a dilute cold cyanide solution for 1 hour. Samples reporting values > 10 g/t are re-analyzed using a 30 g Fire Assay charge followed by a gravimetric finish. All composites utilize a 0.2 g/t cut off and may include internal waste. Some intervals may not add or subtract correctly due to rounding, but are deemed insignificant. Analyses were carried out by ALS Chemex laboratories based in Sparks, Nevada. Blank and standard samples are used for quality assurance and quality control and a review of the results of analyses of the blanks, standards and duplicates by the Company’s Qualified Person indicates values are within normal and acceptable ranges.

About Castle Mountain

Subject to certain obligations, Castle Mountain has 100% of the right, title and beneficial interest in and to the Castle Mountain Venture, a California general partnership, which owns the Castle Mountain property in San Bernardino County, California, (7,458 acres in total). The Castle Mountain heap leach gold mine produced over one million ounces of gold from 1992 to 2001, when mining was suspended due to low gold prices.

The Project hosts a disseminated low sulphidation epithermal system with a gold:silver ratio of 1:1. Gold mineralization is primarily hosted in a complex rhyolite suite and to a lesser extent, in an underlying andesite package and Pre-Cambrian basement rocks. Gold is associated with later rhyolite volcanic activity and zones of silification. Two primary structural orientations are present; N40E and N-S, with a third more subordinate set at N30E. All fault orientations may locally control gold mineralization.

The Project hosts a mineral resource of 182 Mt grading 0.60 g/t Au for 3.15 million ounces in the Indicated category, and 63.7 Mt grading 0.57 g/t Au for 1.06 million ounces of gold in the Inferred category1. Resources were calculated using a cut-off of 0.14 g/t gold.

Static case economics, at a gold price of $1300/ounce, show an NPV (5% discount rate) of $122 million and post-tax IRR of 29.7%3. Initial metallurgical results from column leach and run-of-mine tests are very encouraging with average recoveries of 86% on crushed material4. Final results are expected to be received shortly.

For further information, please contact:

Castle Mountain Mining Company Limited
Marty Tunney
Tel: 416-572-0151
Email: mtunney@83yonge.com