Boulder Lake (elevation 985 metres or 3,232 feet) is a lake in the Tasman District of New Zealand located within Kahurangi National Park. In the late 1890s and early 1900s, water from the lake was used for gold mining purposes for which the lake level was raised by a low dam. British investors lost much money with the venture and large scale mining stopped in 1905 when a flood took out part of the flume. The dam was blown up in the 1930s by a farmer disgruntled with depression-era gold miners stealing his sheep. Boulder Lake is today a tramping destination, with the Department of Conservation maintaining both a hut at the lake and a track to the lake.