The Wintrop occurrence is located at 1554 metres elevation on the east side of Klawala Creek, a southeastern tributary to Keen Creek. Kaslo, British Columbia is located 18 kilometres to the east.
The Wintrop occurrence is also historically part of the former Gibson (until 1923) or Daybreak claim group. The main claims of this group are the Butte (Lot 12410) and Wintrop (Lot 12409) Crown grants.
The first shipments of ore from the occurrence were in 1896 and 1897 by the Gibson Mining Co. No further work was done until 1917 when D.K. May began more development work, which by this time consisted of about 914 metres of drifts on four levels over 122 vertical metres. In 1918, litigation proceedings forced the operation to close and a forest fire destroyed the camp in 1921.
The Daybreak Mining Co. reopened the mine in 1924 which operated intermittently until 1928 when further litigation forced the mine to close a second time. Leasers made small shipments of ore in 1935. The property remained idle until 1949 when the portals were reopened. In 1957, the Daybreak Mining Corp. (1952) Ltd. reopened the workings but no further work was reported. The total workings consisted of five adits between 1548 and 1661 metres elevation. Cream Minerals Ltd. sampled the property in 1997. The property is along a 25 to 80-metre northeast-trending shear zone that has been traced for 3.7 kilometres.
Hostrocks are primarily abundant pure limestones and calcareous argillites together with quartzites of the Triassic Slocan Group. Metasediments, biotite schists and psammites of the Slocan Group are also locally developed adjacent to the Middle Jurassic Nelson batholith to the southeast and the Mount Carlyle stock to the northwest. The Nelson batholith is composed of hornblende potassium feldspar porphyritic granite while the Mount Carlyle stock is composed of potassium feldspar porphyritic granite.
The Wintrop occurrence occupies a bedding parallel, northeast striking, steeply dipping lode structure in the Keen Creek metasedimentary reentrant. Mineralization is chiefly wallrock replacement and better developed where lodes crosscut calcareous horizons.
Five adits explore two parallel structures, the A and B lodes. The lodes are about 100 metres apart, strike 225 degrees and dip 75 degrees northwest and are roughly concordant with bedding. The A lode is a sheared and brecciated zone, 0.6 to 1.5 metres wide, comprised of cataclastic and fault gouge. Mineralization comprises disseminated sphalerite, galena and pyrite in a siderite and quartz gangue. Hematite is also present. The B lode consists of cubic and banded galena, mixed galena and sphalerite, pyrite and minor chalcopyrite in a gangue of hematite and brecciated hostrock. A third or C lode outcrops about 76 metres to the southeast of the B lode and has not been prospected to any great extent.
Production records for the Wintrop occurrence indicate 613 tonnes of ore have been mined intermittently from 1895 to 1935. From this ore, 367,388 grams silver, 103,771 kilograms lead, 53,318 kilograms zinc and 62 grams gold have been recovered.
A grab sample from the dump taken in 1987, assayed 490 grams per tonne silver, 0.22 gram per tonne gold, 0.18 per cent copper, 19.2 per cent lead and 15.8 per cent zinc (Open File 1988-11).
In 2013, Agave Silver Corp. examined the area as the Kaslo property