United Silver Corp. announced the results of an updated National Instrument (NI) 43-101 compliant resource estimate and Preliminary Economic Assessment (PEA) for its Crescent Mine located in the Big Creek drainage of Shoshone County in the Silver Valley of North Idaho, United States of America. This NI 43-101 Technical Report which was independently prepared by SRK Consulting (U.S.) Inc. of Reno, Nevada, USA, determined that USC's Crescent Project silver deposits demonstrate strong economics at the PEA level.

The updated resource estimate indicates the in situ Measured and Indicated resources increased 8.7% and the Inferred resources increased 28.4% on an ounces basis at a silver cut-off grade of 8 ounces per short ton (opt) as compared with the resources in the SRK NI-43-101 Technical Report filed on SEDAR May 31, 2010. The 2013 resource estimate is informed by a larger drill database and the addition of over 2,300 ft of production data from recent development drifting. USC also provided a more extensive database of density determinations, which resulted in an increase in the average density for the deposit.

The updated resource estimate was informed by 279 drill holes and 1,357 chip channel assays from three intermediate drifts completed on the South Vein and one intermediate drift on the Alhambra Vein that were completed since the 2010 resource update was filed. Estimation was carried out using inverse distance weighting of declustered full-vein-width composites. Independent vein wireframes were used to code block percents into model blocks with dimensions 25x25x50 ft (XYZ, respectively).

The Technical Report identifies, estimates and summarizes resources in the three veins incorporated in this updated resource estimate. The three veins are the Alhambra Vein which prior to 2011 has produced over 25 million ounces at an average grade of 27 opt silver. The South Vein, a structure whose existence has been known for more than 50 years, but was not known to host potential economic grade mineralization until surface drilling intercepts identified that mineralization in 2007.

The Jackson Vein, a newly identified vein that was not distinguished from the South Vein during the 2007 through 2010 drilling campaigns. This vein was modeled as a separate vein during the updated resource estimate based on mapping and assay data obtained from three of the intermediate drifts completed during underground exploration and development work in 2011 and 2012. There is a strong indication that the Jackson Vein may be a link vein between the South Vein and the Alhambra Vein which generates a new and focused exploration target for future diamond drilling and underground development.

The deposit model identified strike and dip extensive zones of mineralization on both of the narrow vein structures hosting the Alhambra (2,000 feet on strike and 2,000 feet down-dip) and South Veins (2,000 ft on strike and 1,800 feet down-dip). The mine plan is based on a 34 week mine development schedule to tie the upper Countess Decline to the lower Big Creek #4 Cross Cut. Normal mine production will begin as soon as these headings intersect, enabling a second means of egress from the mine.

During this period there will also be some additional development from the Countess Decline to access the South Vein for stope development on additional mining levels. Production is scheduled from the South, Jackson and Alhambra Veins. The South and Jackson Veins will use a mechanized mining system incorporating primarily uncemented waste rock for backfill.

The plan allows for the mineralized material to be blasted first and removed from the stope. Waste will then be blasted and left in the stope for backfill and to make sufficient room for mechanized equipment to work in the stope. A one foot cemented backfill cap will be placed on the backfill to minimize loss of mineralized material into the fill.

One foot of dilution at zero grade has been incorporated into the schedule and economics. It is expected that Jackson Vein mining will be similar to that for the South Vein. The Alhambra Vein will be mined using a conventional overhand cut and fill stoping method.

Each stope will incorporate two manways into the stope to allow for ventilation and alternate egress and an ore chute. The blasting and moving of mineralized material will be similar to the South Vein with allowances for the narrower vein expected along the Alhambra Vein. Mineralized material will be moved to the chute using slushers.

LHDs will haul the material from the chutes to the ore pass where it will fall to the Big Creek #4 level and be hauled in rail cars to the surface. The Project is very sensitive to silver prices; a decrease in the silver price to $18/oz lowers the IRR to 5%. Increasing the silver price to $22 raises the IRR to 55%.

Each $1.00 increase in the price of silver will improve the IRR approximately 12.5%. SRK recommends diamond drilling from current underground workings to increase the confidence in the mineralized grade and thickness of under-explored areas of the current resource that are included in the mine plan. Additional exploration drilling and drifting is recommended following completion of the secondary exit to resume exploring underexplored areas along the strike lengths of both the Alhambra and South Vein structures.

With the presence of the Jackson Vein as a possible link vein between the Alhambra and South Vein, exploration should be conducted for additional link veins. Additional metallurgical testing is recommended to improve silver recovery in oxidized portions of veins, primarily those areas within about 500 feet of the surface. Testing is also recommended to determine how to improve concentrate grades.

USC also plans to investigate other smelter alternatives to achieve more favorable smelter terms.