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Montero Trenching Returns 4.35 Metres of 17.33% TREO at Wigu Hill Rare Earth Project, Tanzania

TORONTO, ONTARIO--(Marketwire - April 11, 2011) -

NOT FOR DISSEMINATION IN THE UNITED STATES OR OVER UNITED STATES NEWSWIRE SERVICES

Montero Mining and Exploration Ltd. (TSX VENTURE:MON) ("Montero") is pleased to announce trench results from its Wigu Hill Rare Earth Element (REE) project in Tanzania. Wigu Hill is a Light Rare Earth Element (LREE) project with the mineral bastnasite being the dominant rare earth mineral.

At Wigu Hill, prior reconnaissance mapping and sampling identified several priority exploration targets where a total of 209 grab samples were collected which averaged 7.4% TREO. High grade values were traced across the entire 6.2km west-east strike of Wigu Hill, with better values, including a high grade value of 26.2%, occurring on the eastern portion of Wigu Hill. Montero trenching has been focused on the eastern Twiga Target zone which returned the highest grade sample trench interval to date of 27.25% TREO over 0.73m true width.

Dr Tony Harwood, President and Chief Executive Officer of Montero, commented "We are very encouraged by the high grade trench results obtained from the Twiga target in advance of the resource drilling program that is in progress. The mapping and further sampling on other targets has indicated that we have a sizeable bastnasite-bearing system which, with further exploration and drilling – we will bring to account."

Twiga Target

Detailed mapping and trenching on the Twiga target has revealed a complex set of intrusive carbonatite dykes. The large carbonatite dykes are bastnasite rich and occur as NW-SE and E-W dykes sets. Assay results from trenching have returned the positive results Tables 1 and 2 below.

Twiga Target – NW-SE dyke set: This Target consists of a multiple set of anastomosing carbonatite dykes with abundant euhedral burbankite crystals growing from the dyke margins. The dykes are in general near vertical to steeply dipping to the NE at 75º to 80º. Trench values, some of which are listed below (Table 1), are very encouraging.

Table 1: Trench analysis from the NW-SE Dyke Set
Trench
Name
Interval
(metres)
Dip
(deg-
rees)
True
Width
(metres)
TREO
%
La2
O3 %
Ce2
O3 %
Pr2
O3%
Nd2
O3 %
Sm2
O3 %
CT7a 6.05 75 5.84 13.31 6.35 5.37 0.47 1.01 0.06
CT8a 26.20 80 25.80 4.81 2.26 1.89 0.18 0.43 0.03
  Including 9.05 80 9.35 7.02 3.29 2.79 0.26 0.62 0.03
CT9b 19.15 75 18.50 8.03 3.73 3.32 0.28 0.64 0.04
CT9c 4.30 80 4.23 11.72 5.73 4.43 0.42 1.04 0.06
CT10a 4.50 80 4.43 8.85 4.23 3.42 0.32 0.79 0.05
CT13a 5.70 80 5.61 8.60 4.21 3.23 0.32 0.74 0.05
CT14-15 6.50 80 6.40 5.56 2.69 2.12 0.21 0.50 0.03

A map outlining the trench section and plan showing mineralization in the NW-SE oriented carbonatitie dykes can be viewed here: http://www.monteromining.com/projects/pdf/Camp-Twiga-Trench.pdf.

Twiga Target – E-W dyke set: This mineralised E-W dyke set consists of shallower dipping carbonatite dykes that dip between 35º to 47º to the North. The dykes can be traced continuously over 200m at surface and are currently open at both ends. The burbankite crystals in this dyke are abundant and occur as euhedral hexagonal crystals that vary greatly in length from a < 10cm to >20cm but range up to 15cm in diameter and >40 cm in length. Select results were returned as follows:

Table 2: Trench analysis from the E-W Dyke Set
Trench
Name
Interval
(metres)
Dip
(deg-
rees)
True
Width
(metres)
TREO
%
La2
O3 %
Ce2
O3 %
Pr2
O3%
Nd2
O3%
Sm2
O3%
CT7a 9.55 40 6.10 10.44 4.98 4.22 0.36 0.79 0.05
CT8b 8.90 40 5.70 12.43 5.97 5.07 0.41 0.90 0.05
CC1 11.00 47 8.00 11.36 5.42 4.59 0.39 0.88 0.05
  Including 5.00   3.65 18.64 9.02 7.43 0.64 1.42 0.08
CC2 14.00 47 10.23 13.28 6.33 5.38 0.46 1.02 0.06
  Including 5.00   3.65 18.10 8.67 7.28 0.62 1.39 0.09
  Including 1.00   0.73 27.25 13.10 11.00 0.94 2.02 0.12
CC3 10.00 47 7.30 9.15 4.42 3.61 0.32 0.74 0.04
CC4 11.40 35 6.48 6.94 3.33 2.71 0.25 0.60 0.03
CC5 17.70 35 10.15 12.44 6.03 4.83 0.44 1.06 0.06
  Including 7.60   4.35 17.33 8.36 6.81 0.61 1.45 0.08
CC6 3.70 35 2.10 15.91 7.81 5.81 0.60 1.54 0.10
CC7 5.50 35 3.15 9.22 4.45 3.50 0.34 0.83 0.06

The exploration to date on the Twiga Target has returned the most encouraging evidence of bastnasite-rich carbonatite dykes at Wigu Hill to date. Bastnasite is concentrated within Burbankite crystals which grow in varying sizes within the carbonatite dykes together with associated dolomite and some goethite. On most carbonatite dyke outcrops, the burbankite has been observed as small 2mm to 5mm crystals, however, on the Twiga Target, they grow to significant dimensions of up to 30cm. The bastnasite and hence the REE content is enhanced in such zones. The Twiga Target trench values show good continuity with above average values in all of the trenches dug across the E-W Twiga Carbonatite dykes. The peak TREO value from this dyke set is 27.25% TREO and this occurs in Trench CC2.

An aerial view map of Wigu Hill showing the Target areas of interest and photos can be viewed by clicking here: http://www.monteromining.com/projects/pdf/Wigu-hill-photos.pdf.

Other Targets

Detailed geological mapping and trenching was also undertaken on the Tembo Target. In addition reconnaissance geological mapping and selective sampling were undertaken on 2 additional target areas. The results of which are summarised below:

  1. Tembo Target. A set of carbonatite dykes has been defined displaying two main strike directions. The northernmost dykes strike at about 070º over a distance of +150m and the southernmost dykes strike at 300º over a distance of 250m. These dykes vary in width from 0.5m to 5m and are vertical to steeply dipping. The analytical results from this trench program are in progress and not yet available for disclosure.
  1. Chui Target – Located in the central west of the hill, here regional grab samples returned values of 5.5% TREO and 5.7% TREO. Selective sampling of the dykes established values ranging from 1.62% TREO to a maximum of 5.53% TREO. No trenching has been undertaken on this target to date and more detailed mapping and trenching of this area is needed to determine its potential.
  1. Tumbili Target – Located in the central part of Wigu Hill where two trenches have been completed for orientation purposes. A massive carbonatite breccia zone has been identified extending over an area of approximately 300m by >700m on the lowermost flank of Wigu Hill. Given the strike extent of the breccia zone, values from Trench 1 are encouraging, ranging from 1.19% to 7.58% TREO. The carbonatite breccia contains fragments from 1cm to 10cm in diameter, however, it also hosts numerous, medium to large sized, rounded carbonatite clasts highly mineralised with bastnasite. The following graded values were returned from Trench 1:
Table 3: Trench analysis from the Tumbili carbonatite breccia zone
Trench Name Interval (metres) Average Grade (TREO%)
Trench 1 0 - 12.00 2.97
Trench 1 39.0 – 48.00 2.86
Trench 8 4.50 1.50

Exploration has only recently been commenced on the Tumbili target area. However, the carbonatite intrusive dyke material and associated carbonatite breccias are much more extensive than anywhere else described on the Wigu Hill complex to date. Further mapping and detailed trenching on this target will determine the potential size and grade of this target to be followed by diamond drilling.

Discussion on the analytical procedures:

Certified Standard: A certified standard was prepared by AMIS (African Mineral Standards) in Johannesburg, South Africa. This standard was used as reference material in the analysis of the samples reported here.

Analytical Laboratory: The samples presented here were analysed by ALS Chemex in Vancouver after sample preparation was undertaken at their facility in Mwanza, Tanzania. The AMIS certified standard was inserted as sealed packets at intervals of 20 samples. Analyses for high grade REE elements are performed by lithium meta-borate fusion and ICP-MS, an analytical package of 38 elements. Rock forming elements are analysed by lithium meta-borate fusion followed by dissolution of the melt and ICP-AES analysis. An option is available to analyse over limit REE's by ME-OGREE. For this batch of assays numerous samples were analysed for Ce, La and Pr to quantify the higher values of these elements.

Definition of TREO: The use of the term TREO (Total Rare Earth Oxides) in this release includes only the 15 defined rare earth oxides, namely:- Most abundant – CeΓééOΓéâ, LaΓééOΓéâ, NdΓééOΓéâ, PrΓééOΓéâ and SmΓééOΓéâ (referred to as light rare earth oxides). These 5 Rare Earth Oxides make up over 99% of the rare earth element content, particularly for values >1% TREO. Others:- EuΓééOΓéâ, ErOΓéâ, DyΓééOΓéâ, GdΓééOΓéâ, HoΓééOΓéâ, HfOΓéé, TbΓééOΓéâ, TmΓééOΓéâ, LuΓééOΓéâ and YbΓééOΓéâ (Pm was not assayed) are present in minor to trace amounts only. Values for elements such as Y or Nb, are not included and have not been reported here.

QA/QC: Montero has used blanks, field duplicates and one analytical standard to monitor the sampling and analytical quality. Results to date for the blank and field duplicates show acceptable quality for the main REEs of interest. The standard used was prepared on behalf of Montero using material from Wigu Hill and has certified analytical values for Ce, La, Pr and Sm based on analyses from 16 different laboratories. A review of the results reported by ALS Chemex, performed by AMEC, indicates that these meet the required level of analytical quality.

Qualified Person's Statement

The technical information contained in this press release has been reviewed by Mr. Mike Evans, M.Sc. Pr.Sci.Nat., who is a qualified person for the purpose of National Instrument 43-101 and a consulting geologist to Montero.

CAUTIONARY STATEMENT: This news release contains forward-looking information which is not comprised of historical facts. Forward-looking information involves risks, uncertainties and other factors that could cause actual events, results, performance, prospects and opportunities to differ materially from those expressed or implied by such forward-looking information. Forward looking information in this news release includes, but is not limited to, Montero's objectives, goals or future plans, and the estimated timing and cost of the exploration of the Wigu Hill Project. Factors that could cause actual results to differ materially from such forward-looking information include, but are not limited to, those risks set out in Montero's public documents filed on SEDAR. Although Montero believes that the assumptions and factors used in preparing the forward-looking information in this news release are reasonable, undue reliance should not be placed on such information, which only applies as of the date of this news release, and no assurance can be given that such events will occur in the disclosed time frames or at all. Montero disclaims any intention or obligation to update or revise any forward-looking information, whether as a result of new information, future events or otherwise, other than as required by law.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

For more information, contact:

Montero Mining and Exploration Ltd.
Dr. Tony Harwood
President and CEO
+27 83 300 6934
+1 866 688 4671
tharwood@monteromining.com
www.monteromining.com