The Tanglewood Hill prospect is on Tanglewood Hill, about 3.4 kilometres north-northeast of the summit of Lodestone Mountain and 22.5 kilometres west-northwest of Princeton.

The area is underlain by intrusive rocks of the Early Jurassic Tulameen Ultramafic Complex. This ultramafite body intrudes metamorphosed volcanics and sediments of greenschist to amphibolite grade of the Upper Triassic Nicola Group, in the western margin of the Nicola belt. The body trends north-northwest for 20 kilometres, between Grasshopper Mountain and Arrastra Creek, roughly paralleling the contact between the Nicola Group and the Eagle Plutonic Complex to the west. The unit ranges up to 6 kilometres in width, and is at least 3 kilometres wide over most of its length. This intrusion varies in composition from dunite to gabbro, with the most abundant lithology being a coarse-grained pyroxenite.

Tanglewood Hill is underlain by a west-trending mass of hornblende clinopyroxenite covering an area 2.5 kilometres long and 0.5 to 1 kilometre wide. The mass is surrounded by gabbro in the eastern margin of the complex.

Magnetite is sparsely disseminated throughout the pyroxenite. Magnetite also occurs in some two dozen lenses on the west and south slopes of Tanglewood Hill. Eight massive magnetite lenses exposed on the hill's west slope are a few centimetres to 5.5 metres wide. Most are 0.6 to 1.2 metres wide. The lenses strike west to northwest and dip vertically to moderately southwest. The largest lens is estimated to contain 54,000 tonnes of magnetite grading 53.00 to 59.53 per cent iron and 1.89 to 2.12 per cent titanium (an impurity), assuming a length of 90 metres and an average width of 3 metres (Minister of Mines Annual Report 1959, page 50). A magnetite sample from this lens contained 0.02 per cent phosphorous and 0.04 per cent sulphur (Minister of Mines Annual Report 1959, page 51). Inferred reserves for the entire deposit, based on drilling to 1962, are 2,848,000 tonnes grading 16.4 per cent soluble iron (A.H. Lindley, 1962, page 7).

This prospect was explored by Imperial Metals and Power Company Ltd. between 1959 and 1970.