Oro Mining Commences Sonic Drilling to Upgrade and Increase Taunus Gold Resource

VANCOUVER, BRITISH COLUMBIA--(Marketwire - Feb. 21, 2011) - Oro Mining Ltd. (TSX VENTURE:OGR) commenced a 5,000-metre drill program with a sonic drill rig aimed at upgrading and increasing the Taunus gold resource on its wholly owned flagship Trinidad property, located in the state of Sinaloa, Mexico. The Company also reports positive sonic drill results on the remnant heap leach pad, confirming the potential for additional gold ounces to include as a resource.

The sonic drilling has the following objectives:

1. Increase the gold grade of the Eldorado zone
2. Discover additional gold zones in-between the Eldorado and HS zones
3. Continue to define the dimensions and gold grade of the HS zone
4. Target offsets and extensions to the modeled gold zones
5. Target potential high-grade gold feeders

To see a plan map and longitudinal/cross sections showing the location of proposed sonic drill holes, please go to the following link: http://media3.marketwire.com/docs/ogr221.pdf. The sections also graphically reference the recently completed resource block model and defined pit limits.

Heap leach pad sonic drill results

Results from a surface sampling and sonic drill campaign on the historic leach pad at the Taunus deposit confirm there remains a potential in-situ gold resource in the pad. 

A total of 135 surface samples were collected at 25-metre centers on the heap leach pad, each sample taken at a depth of one metre. The results of the surface sampling indicate an average grade of 0.8 g/t gold. In addition, five backhoe trenches, three metres deep, also reported an average composite of 0.8 g/t gold. Gold composites for each of the trenches include TR1: 0.7 g/t gold; TR2: 0.6 g/t gold; TR3: 0.6 g/t gold; TR4: 1.7 g/t gold; and TR5: 0.5 g/t gold. 

As a follow-up, the Company completed eleven sonic drill holes to evaluate the gold grade of the pad material at depth. Assay results of the holes drilled into the pad are shown in the table below:

Sonic Hole No.	From (m	)	To (m	)	Composite Gold Grade (g/t	)
LP1	0		20		0.8
LP2	0		15		0.6
LP3	0		15		0.9
LP4	0		10		0.6
LP5	0		9		0.7
LP6	0		23		0.6
LP7	0		17		0.6
LP8	0		17		0.6
LP9	0		8		1.3
LP10	0		8		0.4
LP11	0		3		0.7

In order to define the amount of mineralized leach pad material at Taunus, a differential GPS survey was conducted that shows 854,000m³ of crushed material exists on the pad. Using an assumed specific gravity of 1.6 for this material, it is calculated that the amount of material is estimated at 1,366,400 tonnes. The potential contained gold in the leach pad is calculated between 27,000 to 32,000 ounces, with a grade range of 0.4 g/t to 1.3 g/t gold, and averaging 0.7 g/t gold.

"Although not in the current NI-43-101 compliant resource, this material would be an additional source of mill feed material," stated John Brownlie, Oro Mining's CEO and COO.

The potential quantity and grade of the material outlined above is conceptual in nature. There has been insufficient exploration to define a mineral resource according to NI 43-101 standards and it is uncertain if further exploration will result in a mineral resource.

Quality Control

Oro Mining maintains a strict quality control program. All samples generated by Oro Mining were submitted directly to Inspectorate, an ISO 9001-2008 certified assay laboratory, for preparation in Durango, Mexico, and analysis in Reno, Nevada. All sonic drill samples submitted for analysis were from splits of half-sawn frozen core. Analysis was conducted on 1 assay ton samples for gold, with a standard, blank and duplicate inserted for every 20 samples submitted. Analysis of gold was by fire assay with AAS finish, and with gravimetric finish on samples exceeding 5 g/t gold. Gary Lustig, P.Geo, is a qualified person as defined by National Instrument 43-101 and has reviewed the content of this press release.

About Oro Mining

Oro Mining is a publicly-listed company on the TSX Venture Exchange with properties located in Sinaloa and Zacatecas, Mexico. Oro Mining's corporate mandate is to advance its projects toward production, while continuing to make exploration discoveries on its extensive property position. The district-scale Trinidad property that hosts the Taunus gold deposit continues to be the focus of Oro Mining's exploration and project development activities. The Company's mission is to create exceptional value for our shareholders through exploration discovery, resource growth, mine development and production, while providing sustainable benefits to our staff, the environment, and the communities where we operate.

ON BEHALF OF THE BOARD OF DIRECTORS

John Brownlie, CEO and COO 

Some statements in this release may contain forward-looking information. These statements include, but are not limited to, statements with respect to future exploration, development and production activities and future expenditures. These statements address future events and conditions and, as such, involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the statements.