The Lexington (Lot 645) is 10 kilometres southeast of Greenwood and 1.1 kilometres north of the International Boundary, at the elevation of 1265 metres, east of Goosmus Creek. Access to the mine is from the Boundary road 1 kilometre west of the Phoenix (082ESE020) - Lone Star (in Washington State) haulage road. The City of Paris (082ESE042) lies 500 metres to the southeast.

Work began on the Lexington claim in 1899. This property is adjacent to the City of Paris property on the west. A total of 360 metres of underground tunnelling was completed to 1901. In the period 1968 to 1981, additional exploration, including trenching and diamond drilling, was completed. In 1980 a new adit was driven midway between the City of Paris and Lexington adits. This work included 210 metres of drifting and crosscut tunnelling and 34 metres of raise development.

Much of the recent exploration has focused on the widespread, low grade copper mineralization associated with the quartz porphyry intrusion on the Lexington, City of Paris, Lincoln and adjacent claims. This 'porphyry' mineralization is mostly contained within a 900-metre long, 300-metre wide segment of the quartz porphyry exposed between the main ultrabasic intrusion and a smaller subparallel serpentinite splay near Goosmus Creek. The principal mode of occurrence of the main ore minerals, pyrite and chalcopyrite, is in fractures and disseminations and, to some extent, in quartz stockworks. Anomalous copper values have also been obtained in the serpentinite splay adjacent to the quartz porphyry intrusion near Goosmus Creek, just below the Lexington portal. This sheared serpentinite contains interfoliated impregnations and massive lenses of pyrite, chalcopyrite and magnetite.

The McCarren-Goosmus creeks area is underlain by a southeasterly striking 1.6-kilometre wide belt of Paleozoic(?) gneiss and schist bounded both north and south by zones of Paleozoic or Early Mesozoic metavolcanic and metasedimentary beds. These rocks are cut by a wide variety of igneous intrusions, including a porphyritic quartz- feldspar porphyry stock and a few large serpentinite and gabbro dyke-like bodies. Also, dykes and irregular-shaped diorite intrusions are found throughout the area cutting many of the units. The youngest rocks consist of a few pulaskite and basalt dykes and a small outlier of Tertiary conglomerate.

The rocks of the gneiss-schist belt form a basement complex of thinly layered quartz-chlorite schist, massive lenses of pure metaquartzite and graphitic quartzite, minor muscovite schist and carbonated schist, and a prominent zone of chlorite-amphibole schist. Sharp-crested, shallow plunging folds are locally well developed in the laminated units. The gneissosity and foliation are generally inclined to the northeast, with dips ranging from about 20 to 60 degrees.

The volcanic and sedimentary units which overlie the basement complex comprise a lower zone of basalt and andesite lava, an intermediate zone of carbonaceous phyllite and an upper zone of quartz wacke and conglomerate - the total sequence being more than 304 metres thick. The overall disposition of these units is almost horizontal, although some beds are steeply inclined on the limbs of minor folds.

The oldest igneous intrusions, probably Early Mesozoic age, consist of an assemblage of genetically related small stocks and hypabyssal felsic intrusions mapped as quartz-feldspar porphyry, quartz porphyry, felsite and schistose felsite. The largest of these units is a body of quartz-feldspar porphyry located near the junction of McCarren and Gidon creeks. An elongated composite quartz porphyry felsite intrusion (the Lexington property "dacite") follows the general course of Goosmus Creek and appears to be an easterly extension of the quartz-feldspar porphyry stock.

Late intrusives on the Lexington property include Cretaceous(?) serpentinite masses, early Tertiary diorite and alkali-diorite dykes and stocks, and pre-diorite andesite dykes(?). The felsic igneous rocks (quartz porphyry, quartz-feldspar porphyry) are intruded by a large serpentinite dyke-like body which extends northwest from the vicinity of the Lone Star mine south of the International Boundary to McCarren Creek, a distance of about 7.2 kilometres. This ultramafic body as well as a similar-sized intrusion at Mount Wright and several other smaller lenses, consist primarily of an antigorite-rich serpentinite. Early Tertiary fine to medium-grained diorite dykes and a number of irregular-shaped intrusions are found throughout the area and cut the felsic intrusions and units of the metamorphic complex.

The overall disposition of the rock types on the property is that of a gently to moderately dipping sheet (quartz porphyry or "dacite") enclosed by, and locally intruded by serpentinite. The general dip of the major contacts is 20 to 30 degrees to the northeast, with the strike changing in a gentle arc from northwest in the south, to nearly east-west in the north. Foliation in both the "dacite" and serpentinite generally parallels strike, but is more steeply dipping (30-60 degrees to the northeast). The "dacite"-serpentinite package is in turn cut by northeast to north striking, steep normal faults, a moderately northwest dipping thrust? fault, a probable east trending vertical fault and unknown amount of local contact shearing and faulting observed in talc-rich zones of the serpentinite.

Gold-copper-(silver) mineralization occurs in several styles in the Central Camp, an area that has been prospected and mined since 1890 when the region was first explored. Most mineralization is related to local structural environments and virtually all significant mineralization occurs within the quartz porphyry to felsite unit (locally termed "dacite"), at or close to its contacts with either the hanging wall or footwall serpentinites. The principal varieties of mineralization include: 1) major quartz veins and vein systems, 2) veins, silicified zones and replacements, 3) fracture-fill and disseminated sulphides and 4) mineralized shear zones in serpentinite.

The No. 7 mine (082ESE043) is on the most productive vein (style 1 mineralization) located on a ridge south of McCarren Creek, approximately 2.5 kilometres north-northwest of the Lexington adit which is on the Lexington claim (Lot 645). The vein crops out along the north contact of a narrow appendage of a serpentinite intrusion. Two periods of intermittent production were recorded from this mine, 1901 to 1913, and 1934 to 1945. The City of Paris mine (082ESE042) is on a vein system (style 1 mineralization) near the south contact of the serpentinite intrusion, about 3 kilometres south-southeast of the No. 7 mine and 500 metres south-southeast of the Lexington adit. The City of Paris portal is on the Number Four claim (Lot 791), with the underground workings extending easterly onto the City of Paris claim (Lot 622) and the Lincoln claim (Lot 621). Production of ore was mostly in the year 1900 with some ore shipments also recorded from 1937 to 1940. The Lincoln vein is exposed on the south side of the serpentinite and appears to be the vein followed by the main northwest drift on the bottom level of the City of Paris mine. A small shipment of ore was made from the Lincoln portal located on the Lincoln claim (Lot 621), 182 metres east of the City of Paris mine. A 76-metre adit was driven on a pyrite-chalcopyrite vein on the Lexington claim.

Style 2 mineralization is exemplified by the so-called Mabel veins (082ESE149), located between the No. 7 and City of Paris mines. These veins consist of a series of small, auriferous quartz stringers. Production in 1937 was from an inclined shaft sunk on a narrow zone of silicified schist. Some of the silicified zones and quartz stringers in the Mabel area are related to broader, replacement-type sulphide deposits apparently associated with large Tertiary diorite dykes.

Style 4 mineralization is evident west of the Lexington portal, where high copper grades occur locally in serpentinite adjacent to a quartz porphyry intrusion. Shears within the serpentinite contain pyrite and chalcopyrite. Assays across a 30-metre width range from 0.36 to 0.76 per cent copper (Geology, Exploration and Mining in British Columbia 1970).

The Lexington property now includes most of the workings in the Central Camp. Recent exploration is focused on style 3 mineralization, widespread low-grade copper mineralization associated with the quartz porphyry (dacite) in the City of Paris area. This "main zone" mineralization is contained roughly within a 914-metre long, 304-metre wide segment of the quartz porphyry exposed between the main serpentinite intrusion and a somewhat smaller serpentinite body near Goosmus Creek. The principal mode of occurrence of the main minerals, pyrite and chalcopyrite, is in fractures and disseminations and to a less extent in quartz stockworks. The rock is commonly leached at surface, with fracture faces being coated with limonite and malachite or black manganese oxide. Fractures are strongly developed locally and the intensity of mineralization appears proportional to the relative development of fractures. A statistical study of fractures in the quartz porphyry shows two fracture directions, a dominant direction striking 125 degrees, dipping 55 degrees northeast, and a weaker system striking 160 degrees, dipping 50 degrees northeast. Cross-joints and tension fractures commonly strike about 030 degrees and dip 65 degrees northwest and 101 degrees and dip steeply, respectively. The broadest exposed area of fair to good mineralization is centred about 243 metres north of the City of Paris portal. Smaller areas are found 152 metres south of the Lincoln portal (Geology, Exploration and Mining in British Columbia 1970). Surface and underground exploration work on the Lexington property has been continuous since the 1960s.

Candol Developments drilled 10 holes on the property in 1989.

In 1993, proven mineable reserves were stated as 131,500 tonnes grading 9.6 grams per tonne gold and 1.48 per cent copper (Northern Miner, February 1, 1993). The mineralized zone consists of three subzones, the Main, Vacher and Golden Cache. Ore reserves for this property, according to 1981 estimates, indicate 313,527 tonnes, grading 5.44 grams per tonne gold and 1.96 per cent copper, calculated using a 15 per cent dilution factor. An additional 110,000, tonnes grading 1.99 grams per tonne gold and 0.92 per cent copper, is amenable to possible open pit mining (International Prospector & Developer Magazine, Mar/Apr 1982).

Britannia Gold Corporation and Bren-Mar Resources Ltd. widened the Grenoble adit and completed work on a 600-metre decline to the Main zone containing a drill indicated reserve estimated at 162,000 tonnes grading 8.9 grams per tonne gold and 0.96 per cent copper. (Northern Miner, February 26, 1996 and Information Circular 1996-1, page 15). The decline is being extended a further 235 metres to allow underground diamond drilling of the 'lower' Main zone.

In 1897 the Lone Star (on the U.S. side) produced 1,700 tons of ore. Intense development and production from 1898 to 1901 saw ore shipped from the Lexington, City of Paris and other proximal claims to the Granby smelter. In 1902, underground work commenced on the No. 7 Mine culminating in about 1,000 tons shipped by 1903. In 1909, the property was acquired by Consolidated Mining and Smelting Co. where they continued underground development, installed an aerial tram to the Boundary Falls mill and shipped over 5,000 tons between 1910 and 1913.

The B.C. Copper Co. acquired the Lone Star in 1908 and also built an aerial tramway to the Boundary Falls smelter.

Between 1910 and 1918, 160,000 tons were shipped. Low copper prices forced the closure of all of the mines in the area by 1920.

Precious metal interest began in the 1930s. A few tons were shipped from the City of Paris Group to Trail between 1927 and 1940. In addition, a new shaft was sunk on the Mabel claim where a few tons were produced.

In 1951 Attwood Copper Mines Ltd. started assembling a large land package in the area. By 1953 they acquired the Lone Star from Eugene Mining Co. Attwood opened the old workings and conducted mapping, sampling and diamond drilling. In 1955, Granby Mining optioned the Richmond and Lone Star from Attwood and conducted diamond drilling at the old workings. In 1959, an airborne geophysical survey was flown over the Canadian portion of the property by Lundberg Exploration. The Richmond and Lone Star were optioned to Moneta Porcupine in 1961 who conducted drilling and geophysical surveys.

In 1962, King Midas Ltd. assembled many of the old Crown-granted claims, carrying out surface and underground exploration on Lincoln and Mabel.

From 1967 onward there has been more intense exploration and development on the property with minor lulls.

Between 1967 and 1970 Lexington Mines Ltd. acquired the Lexington and expanded the land package to include all of the current Canadian claims. Lexington Mines Ltd. completed an extensive program of geological, geochemical and geophysical surveys, bulldozer trenching, diamond drilling and underground rehabilitation resulting in the discovery of the Grenoble deposit on the Lexington claim and others. During this period Silver Standard and Kenogamisis Gold Mines optioned the Richmond, exploring the ground between Richmond and Lone Star by drilling and geophysics.

Falconbridge surveyed the Lone Star and claims to the south in 1969. Israel Continental conducted a drill program on Richmond and Lone Star from 1970 to 1971. Granby optioned the Lexington in 1972 forming a joint venture with Coastal Mining and optioned the Richmond and Lone Star. The Lexington received drilling in 1972, Lone Star in 1973-1975 and Richmond in 1976. In 1974, Aelenian Resources optioned Lexington and drilled in the Grenoble deposit area in 1975. Granby Mining Co. open pitted the Lone Star trucking about 400,000 tons to Phoenix during 1977-1978.

Azure Resources acquired the Lone Star in the early 1980s, conducting surface exploration and drilling in 1981-1985. U.S. Borax and Kennecott Exploration carried out the last detailed geological mapping and drilling program on the Lone Star in 1989-1991, bring the total number of percussion and diamond drill holes in the Lone Star area to date to in excess of 300.

In 1979 Grenoble Energy acquired the key Lexington claims and drove a test adit into the Grenoble deposit in 1980. Twenty underground holes were drilled into the Grenoble deposit from the new workings. In 1981 Teck Corp. optioned Grenoble’s holdings in addition to the Richmond area claim and completed 47 drill holes by 1983. Between 1984 and 1986 Canadian Pawnee Oil Corp. acquired much of the property on the British Columbia side of the border. Surface geophysical and geochemical surveys and 33 diamond drill holes were completed in 1986-1988.

Britannia Gold Corp. assembled the various holdings into the current property in 1991. Between 1993 and 1997, Britannia Gold conducted a systematic exploration program including data compilation, detailed mapping of the Goosmus Shear Zone, surface induced polarization and magnetometer surveys, underground rehabilitation and mapping, re-logging of previous drill holes, bulldozer trenching and diamond drilling.

In 1995, Bren-Mar Resources Ltd. formed a joint venture with Britannia Gold Corp. and together they completed a 900 metre long decline and 29 underground drill holes from 1996-1997 to assess the Grenoble deposit mineralization. The decline, crosscuts into mineralization and underground drilling were designed for detailed definition of the ore body geometry, evaluation of grade continuity and assess ground stability conditions, all necessary for detailed planning of possible production stoping in the future, ie. precise mining method, location of test stopes and pillars, and ground support methods. On April 3, 1997 a permit was granted to conduct a 2,000 tonne bulk sample on the Grenoble deposit, however, Britannia Gold Corp. and Bren-Mar Resources Ltd. did not initiate the bulk sample.

In August 2002, Gold City acquired the Lexington Property. Since then Gold City has compiled all water quality sampling on the property and continued the water quality sampling, conducted metallurgical testing of the Grenoble and conducted a six hole surface diamond drill program and rehabilitated the portal and the initial 25m of timbering.

In 2003, Gold City completed 906.6 metres of drilling in 6 HQ holes to attain additional information to refine resource calculations for the Grenoble deposit and for metallurgical testing. Numerous zones of pyrite-chalcopyrite veining were encountered in dacitic host rocks with impressive results, including one 4.57 metre interval that assayed 28.68 grams per tonne goldand 1.17% Cu in hole 03GCD-01 (Exploration and Mining in BC 2003, page 35).

Gold City Industries Ltd’s Greenwood Gold project, which incorporates the Lexington and Golden Crown 082ESE032, 033) properties, was extremely active again in 2004. Trenching and diamond drilling were carried out at both sites. The company also received permission to construct a 200-tonne per day mill on the Zip property, in the same area. Following commissioning of the mill, a 10 000-tonne bulk sample will be collected from the Lexington property via the Grenoble deposit adit. Mineralization on both properties is vein-hosted. A positive production decision is anticipated in 2005 following processing of the Lexington bulk sample. Work at the Lexington in 2004 included 4847 metres of diamond drilling, some of which resulted in a significant extension to the length of the Grenoble deposit.

At a cut-off of six grams per tonne gold equivalent, the Lexington indicated resource consists of 152,600 tonnes grading 10.3 grams per tonne gold and 1.6 per cent copper, or a gold equivalent of 13.8 grams per tonne. At the same cut-off, the inferred resource is 58,300 tonnes grading 10.2 grams per tonne gold and 1.7 per cent copper, or a gold equivalent of 13.8 grams per tonne (New Release, Gold City Industries Ltd., May 17, 2004).

In 2005, the Lexington Property of Gold City Resources covered a series of former mines, advanced stage deposits with resources, mineral prospects and exploration targets all associated spatially and probably genetically to the No. 7 Fault Zone. Past workers have termed the portion of the No. 7 Fault Zone on the property, the “Goosmus Shear Zone”. The mineralized trend runs from the Lone Star Mine and the Northwest Zone in Washington State, the Richmond Zone, City of Paris Mine, Grenoble deposit, Lexington Mine, TG-81 target, Golden Cache, Vacher and finally the No. 7 mine (082ESE043) in the northwest. The Mabel and Oro prospects occur between the No. 7 and Vacher but lie outside of the Property holdings.

In 2006 Merit Mining reported an updated Measured and Indicated combined resource estimate of 297,000 tonnes grading 8.36 grams per tonne gold and 1.35 per cent copper and an Inferred resource of 45,000 tonnes grading 6.58 grams per tonne gold and 1.03 per cent copper, both at a cut-off of 6 grams per tonne gold equivalent (www.meritminingcorp.com).

On May 8, 2008 the Mine Operating Permit for operating at 72,000 tonnes per annum was received from the Province of BC and commercial production commenced on June 1, 2008.

In 2016, an updated mineral resource was reported at 372,000 tonnes measured and indicated grading 6.47 grams per tonne gold and 1.05 per cent copper and 12,000 tonnes inferred grading 4.42 grams per tonne gold and 1.03 per cent copper, using a 3.50 grams per tonne gold equivalent cut-off grade (Cowley, P. (2017-06-02): Updated Preliminary Economic Assessment on the Greenwood Precious Metals Project).