The Bonanza-Golden Eagle Property is located within the Harquahala Mining District of the Little Harquahala Mountains, La Paz County, Arizona.
Terraco controls the Harquahala-Bonanza and Golden Eagle mines, historically the largest gold producers of the district, as well as the prospective claims on the structural contact zone.

The Harquahala Mining District was organized in the late 1880's.  The Harquahala-Bonanza Mine (otherwise known as the Consolidated Bonanza Lode) was discovered in 1888.  The Bonanza Mine is considered to have been the most productive mine of the district.  The Golden Eagle Mine was discovered and mined after the original strike at the Harquahala-Bonanza. 

The geology of the Little Harquahala Mountains near the Bonanza-Golden Eagle Property consists of Lower Paleozoic quartzites, calcareous mudstone with interbedded shales, and thick-bedded to massive limestones to dolomites of the Cambrian Bolsa Quartzite, Cambrian Abrigo Formation, and Devonian Martin Formation, respectively. The lower Paleozoic units are in low-angle (reverse and normal) fault contact with underlying Tertiary to Cretaceous granitic intrusives.   Detachment contacts are locally mylonitic and extensively sheared and brecciated.  The overlying sediments are strongly folded on regional to outcrop scale, cut by high angle normal faulting, and are structurally well-prepared to host precious metals ore-bodies. 

The ore bodies developed at the Bonanza and Golden Eagle mines were primarily detachment fault-related, sediment- and intrusive-hosted gold deposits.  Mineralizing fluids, following high and low angle structures, are inferred to have migrated up to and across low angle normal faulting  where structural preparation and reactive host rock chemistry were conducive to the formation of significant ore-bodies.  Historically at the Harquahala Mine, gold and silver ores were extracted from altered structural zones along the detachment (originally described as a thrust) and replacement bodies in lower Paleozoic, calcareous quartzites, muddy limestones, dolomites, and shaley units.  The sediment-hosted ores were focused along high angle feeder structures and averaged close to one troy ounce per ton gold and more than one half  troy ounce per ton of silver.  Underground working were sampled in the early 1980's revealing a large area (>= 250 foot length in workings at the 71 foot level)  in altered, calcareous sandstones and quartzites of the Bolsa Quartzite.  Assays, from ALS Chemex, of underground sampling conducted in February 2005 confirmed or improved upon the earlier sampling results.

There is a significant potential to expand known mineralization at the Harquahala-Bonanza, Golden Eagle, and other known targets within the current property position.  This potential has never been adequately tested.  Exploration of the Bonanza Property using modern drilling methods has been limited in scope and sporadic in nature. Widespread alteration and other known workings/prospects over a multi-square mile area provide substantial, additional exploration potential for a district scale opportunity.