The Rob Roy and Highland Chief Crown grants are located on Galena Creek about 1 kilometre up from Ferguson Creek.
There are five major bands of limestone in the area which are known locally as the Black Warrior, Silver Leaf, Ellsmere Ledge, Horne Ledge and Surprise limestone. The Black Warrior was mapped by the Geological Survey of Canada as the Badshot Formation. It is now thought that all these bands are part of the Lower Cambrian Badshot Formation, repeated by folding. These bands are interlayered with schist and phyllites of the Cambrian to Devonian Index Formation, Lardeau Group.
In 1993, Assessment Report 22917 reported that the Horne Ledge group included Crown grants Rob Roy (Lot 4288), Highland Chief (Lot 4290), Centre Star (Lot 4239) and Morgan (Lot 1301) (082KNW210). This report further states that according to prospector Eric Denny, there are at least five mineralized zones along the Horne ledge. These four non-contiguous claims may represent some of the mineralized locals.
In each year from 1893 to 1898 some mention is made of the Horne ledge or Horne group (082KNW210). In 1899, the Rob Roy and Highland Chief were acquired by the Scottish Canadian Mining and Development Company. The main vein is about 3.7 metres wide with a heavy iron capping and lies at the contact of limestone and slate. Two smaller leads run parallel about 15 metres apart and contain small veins of galena. By 1900, a 91-metre crosscut had been done and "concentrating ore" was encountered in the workings.
In general, the character of the Horne ledge mineralization is reported to be almost impossible to determine due to the heavy oxidation and leaching of the mineralized zone. Only at certain localities did the outcrop show visible mineralization. Where observed, the mineralization appeared as massive galena with sphalerite and minor pyrite, pyrrhotite and trace amounts of chalcopyrite.
The area was largely inactive until the 1980s when a number of the old workings came into the possession of Jack and Eric Denny, through purchase or staking. Please see Silver Leaf (082KNW204) for a description of the common work history of the area.
In 2007, Roca Mines Inc. optioned the Ellsmere (MINFILE 082KNW081) and Horne claims and completed a program of soil sampling. The following year two drill holes, totalling 437, were completed on the claims.
Also during 2006 through 2009, Mineral Mountain Resources Ltd. completed programs of prospecting, geochemical (soil, silt, talus fines and rock) sampling and an airborne geophysical survey on the area as the Kootenay Arc property.