Mr. John Heslop of Thundermine reports

THUNDERMIN AND CORNERSTONE REPORT FINAL DRILL RESULTS FOR THE FIRST HALF OF 2011 AT LITTLE DEER AND ANTICIPATE THE COMPLETION OF AN UPDATED NI 43-101 MINERAL RESOURCE ESTIMATE BY JUNE 30, 2011

Thundermin Resources Inc. and 50-per-cent joint venture partner Cornerstone Resources Inc. completed on May 28, 2011, a 25-hole, 12,690-metre diamond drilling program that commenced on the Little Deer copper deposit on Dec. 1, 2010. Assay results for the last 10 holes of the program are presented in the associated table. Results for the first 15 holes of the program were presented in news releases dated Jan. 20, March 22 and April 26, 2011. The deposit is located approximately 10 kilometres north of Springdale in north-central Newfoundland.

         LITTLE DEER DRILL RESULTS (2011)

Hole No.        From        To    Interval        Cu
                 (m)       (m)     (m) (i)       (%)

LD-11-53       596.5     597.0         0.5       3.3
And            603.7     605.2         1.5       1.7
And            628.9     629.8         0.9       3.4
LD-11-54       782.2     786.9         4.7       1.0
And            817.7     823.2         5.5       0.9
LD-11-55       973.8     977.9         4.1       1.1
LD-11-56       728.1     729.6         1.5       1.3
LD-11-57                                         NSV
LD-11-58       149.9     150.5         0.6       2.5
And            173.0     175.9         2.9       3.5
LD-11-59       178.0     179.0         1.0       3.0
And            185.1     191.1         6.0       2.1
Including      189.0     190.1         1.1       8.6
LD-11-60                                   Abandoned
LD-11-61        86.7      87.3         0.6       1.2
LD-11-62        73.4      74.8         1.4       2.2
And             87.0      89.7         2.7       1.6


Notes:
1) (i) The reported copper intersections are core 
lengths. The true thicknesses of the various 
copper intersections are highly variable due
to the stringer nature of the mineralization. 
Management, however, believes that the true 
thicknesses of the drill intercepts of the
reported holes average approximately 70 per cent
to 75 per cent of core lengths.
2) Hole LD-11-58 also intersected 18.6 grams per 
tonne (g/t) Ag and 0.4 g/t Au over 2.9 metres
from 173.0 metres to 175.9 metres.
3) NSV -- no significant values.

The primary purpose of the current drill program was to increase the estimated mineral resources in the deposit to the five-million-to-six-million-tonne range and to confirm the continuity of the copper mineralization in certain areas of the deposit. The potential increase of the current mineral resources is conceptual in nature, and it is uncertain whether the recently completed exploration drilling will result in an expansion of this mineral resource.

Holes LD-11-53, 54, 55 and 56, which were drilled to further define the eastern margin of the deposit, all intersected variable amounts of copper mineralization over varying widths. Hole LD-11-57, which was drilled at depth along the eastern margin of the deposit, intersected an extensive chlorite alteration zone but failed to intersect any significant copper mineralization.

Holes LD-11-58, 59, 61 and 62, which were drilled approximately on the negative-100-metre elevation to confirm historic drill data in the upper central portion of the deposit, all intersected variable amounts of copper mineralization over varying widths. The best intersections were 3.5 per cent Cu over a core length of 2.9 metres in hole LD-11-58 and 2.1 per cent Cu over six metres, including 8.6 per cent Cu over 1.1 metres, in hole LD-11-59. Hole LD-11-60 was abandoned due to drilling difficulties.

John B. Heslop, president and chief executive officer of Thundermin, said: "We are pleased with the overall results of the recently completed drill program as drilling continues to intersect good grade copper mineralization over minable widths. We were also able to establish continuity of the copper mineralization in certain areas of the deposit and have successfully reproduced copper grades and intervals in the area of the deposit where we have recovered a large amount of historical information from the archives. We look forward to the completion of a revised National Instrument 43-101 (NI 43-101) mineral resource estimate for the deposit in the next couple of weeks."

P&E Mining Consultants Inc.

As announced on April 26, 2011, P&E Mining Consultants Inc. of Brampton, Ont., has been retained to complete an updated NI 43-101-compliant mineral resource estimate for the deposit. This updated resource estimate will include results from 48,432 metres of drilling in 82 holes completed by Thundermin and Cornerstone since June, 2007, and all assay information from a total of 86 surface and 122 underground historic drill holes that were recovered from the archives of the Newfoundland and Labrador Department of Natural Resources. The historic holes were all drilled by British Newfoundland Exploration Co. between 1961 and 1970. Additional details on the deposit can be found in numerous Thundermin and Cornerstone news releases dated between May 1, 2007, and April 26, 2011, which are on each company's website and on SEDAR.

P&E has also been retained to complete an internal scoping review for the Little Deer project. This review will evaluate a range of potential mining and operating scenarios for the project and provide the management of Thundermin and Cornerstone with preliminary information on the economic viability of developing a new copper mine at Little Deer.

Mineral resource estimate

On Oct. 13, 2010, Thundermin and Cornerstone announced that an updated NI 43-101-compliant mineral resource estimate had been completed by Scott Wilson RPA under the supervision of Reno Pressacco, MSc (A), PGeo, senior geologist for Scott Wilson RPA and an independent qualified person (QP) in accordance with NI 43-101. Scott Wilson RPA estimated that the deposit contains indicated resources of 1,150,500 tonnes at an average grade of 2.8 per cent Cu within the Little Deer zone, additional inferred resources of 1,227,300 tonnes at an average grade of 2.2 per cent Cu within the Little Deer zone and 1,108,200 tonnes at an average grade of 1.9 per cent Cu within the Footwall zone. An NI 43-101-compliant letter report entitled Mineral resource update for the Little Deer project, dated Sept. 30, 2010, to support the updated mineral resource estimate, is available on Thundermin's and Cornerstone's websites.

Metallurgy

On Oct. 19, 2010, excellent metallurgical results from scoping level testwork on core samples from the deposit were announced. This work, which was undertaken at SGS Lakefield Research Ltd. of Lakefield, Ont., indicates that a saleable, high-grade copper concentrate grading over 28 per cent copper with over 97-per-cent recovery and free of any deleterious elements can be produced from the deposit.

Qualified person

Andrew Hussey, PGeo, project geologist and lands manager, Cornerstone Resources, is the QP responsible for supervising the drilling program and the compilation of all of the historic data on the deposit for the purposes of NI 43-101. Mr. Hussey has also reviewed the contents of this news release for accuracy. All holes drilled by Thundermin and Cornerstone are NQ in size. Bulk density measurements, rock quality designations and photographic logging of significant mineralized intersections are performed systematically prior to assaying. The core is logged, and the mineralized sections, where appropriate, are sawn in half at a core logging facility in Springdale. Half of the core is submitted for analyses to Eastern Analytical Ltd., an independent and qualified assayer located in Springdale, Nfld., and the remaining half of the core is kept for future reference. Blanks, duplicates and standards are routinely used as part of the assay procedures.

Little Deer joint venture

Thundermin, the operator, and Cornerstone have the option on a 50:50 basis to earn a 100-per-cent interest in the Little Deer copper deposit and adjacent property from Weyburn Investments Ltd. Thundermin, under its joint venture agreement with Cornerstone, has the right to increase its interest in the Little Deer property to 75 per cent by completing a feasibility study and by arranging 100 per cent of the necessary bank financing required to place the property into commercial production. Details on the deposit and the terms of the agreement with Weyburn can be found in numerous news releases and on Thundermin's and Cornerstone's respective websites and on SEDAR.

Junior exploration assistance program

Thundermin and Cornerstone would like to acknowledge the financial support received from the junior exploration assistance (JEA) program of Newfoundland and Labrador in carrying out a portion of their work on the Little Deer property.

We seek Safe Harbor.