Ice can become “hidden”, i.e. buried, by the superimposition of rock debris on a glacier or where rock debris may incorporate interstitial ice. Because it is obscured, problems result from a lack of understanding of the extent and continued activity of such ice. Landforms may be associated with this phenomenon and can be used as indirect evidence of its existence. A rock glacier can contain glacially-derived, buried ice as well as interstitial ice. We show, with examples, how such rock glaciers can be identified and provide information on the extent and possible volume of hidden ice in marginally glacierized and permafrost areas. In most cases, recognition of topography is sufficient, although time-separated aerial photographs may be necessary to locate the extent of ice. These are generally preferable to, and more cost effective than, most detailed on-site determinations of ice extent. It is possible to incorporate and extend knowledge of hidden ice in glacier mapping and inventory projects.