9
geophysical work prior to the merger. Exploration was focused initially in the southwest Bull Hill
Area that was identified and explored previously by Hecla Mining Company from 1987 through
1991. Most of the core drill holes targeted strike and dip extensions of the carbonatite dike
swarm at the Bull Hill SW target. RER conducted limited drilling programs in 2004, 2005, 2007,
and 2008. From 2009 through 2011, RER conducted aggressive core drilling campaigns in
order to expand and upgrade the deposit at Bull Hill, as well as to test additional target areas,
including Bull Hill NW, Whitetail Ridge, Bull Hill West, Carbon, and East Taylor. Geophysical
surveys and geologic mapping and sampling were carried out in order to identify additional
targets and improve geological understanding of controls on mineralization. In 2010, 2011, and
in 2012, RER also drilled large-diameter (PQ and HQ-size) core holes that provided bulk sample
material for metallurgical testing.
Between 2004 and 2012, a total of 150,094 feet – ft. (45,749 meters) was completed in 193 core
holes that range in depth from 88 to 1,886 feet (27 to 575 meters) in the exploration and
development drilling programs. The 2009 exploration program marked the beginning of a
dramatic increase in the total drilling compared to prior years (2004 – 2008 total of 15,388 feet
or 4,690 meters in 20 core holes), as well as additional geological mapping and geophysical
surveys in the Bull Hill and Whitetail resource areas. The aggressive 2010, 2011, and 2012
exploration and drilling programs were designed to continue the expansion and upgrade of
existing resources, as well as the identification and exploration of new targets. Geological
mapping and geophysical surveys were directed towards improving understanding of the
surface and structural signatures and controls on mineralization within the deposits and Project
Area. RER conducted ground radiometric and soil surveys in 2009 and 2012, and controlled
source audio-magneto-telluric (CSMAT) surveys over both rare earth and surrounding precious
metal target areas in 2010 and 2011. Geological mapping, rock chip sampling, and radiometric
surveys were carried out in areas with newly created exposures of subcrop to outcrop, including
drill access roads and drill pads. Trenches excavated during the 2011 field season exposed
subcrop and outcrop in the Bull Hill Area. The trenches were subject to detailed mapping,
sampling, and radiometric surveys. Borehole televiewer surveys were conducted on selected
drill holes during the 2011 and 2012 drill season and provided additional detailed geological and
structural information.
4.3
ACCESS
4.3.1 Access Route
The preferred access route leading to and from the Mine Area is the Miller Creek Access Route
as shown on Map 4.2-1. The access route will be used to transport personnel, equipment, and
supplies to the Mine Area and to transport pre-concentrate from the PUG Plant to the Hydromet
Plant near Upton, Wyoming.
In 2011, RER evaluated 11 potential access routes to the Mine Area to select a route which
would provide safe, year-round access while minimizing impacts to the environment and public
use. The analysis identified two preferred routes (Miller Creek Road and Warren Peak Road),
both connecting the Mine Area with U.S. Highway 14. RER has selected the Miller Creek
Access Route with the goal of minimizing safety concerns and potential environmental impacts
(see Map 4.2-1).
