The Oyu Tolgoi (OT) copper and gold project is located in the Southern Gobi region of Mongolia and is being developed by Oyu Tolgoi LLC. The project is expected to be a significant contributor to regional development and is jointly owned by the Government of Mongolia. The geology of OT is structurally complex with several tectonic reactivation events within Devonian and Carboniferous rocks. The aim of this paper is to describe the use of cutting-edge data acquisition technologies allow OT to systemically model and validate the lithology, fault structures, dykes and cross-cutting relationship. Since the application of Adam Tech, Leapfrog Geo and other spatial tools at the OT open pit mine, the geological and structural models of Oyut deposit have been interpreted and revised in detail making the most of ore body knowledge. The OT Surface Mine Geology team collect structural data from pit walls and integrate this data into structural geology models in order to predict further slope failures. However, pit wall access is sometimes restricted due to safety or operational concerns, so comprehensive face mapping is not always achievable in the field. The solution has been to use the remote 3D structural geological data capture package developed by ADAM Technology Adam Tech is routinely deployed to collect geological and structural data on all exposed open pit walls. Subsequent interpretation and 3D modelling is undertaken within the Leapfrog Geo software package. The general workflow is to create all 3D geological surfaces within Adam Tech prior to export into Leapfrog Geo (as an object file with colour photos). Within Leapfrog Geo, interpretation is performed by comparing the current mining bench with overlying benches, as well as with the existing fault and geology model interpretations. There are many advantages of using Leapfrog Geo to update the structural model, particularly on large bench stacks where interpretation of pit wall surfaces can extend over ten benches and requires simultaneous display of multiple data sources Leapfrog Geo allows display of the original wall with coloured photos, creating disks, polylines and points. To further improve remote geological data capture and modelling, OT have recently implemented the use of geo-referenced drone imagery and (laser) survey scans for refining structural model updates in Leapfrog Geo. CITATION: Amarbold, T, Dorjbat, L, Erdenebayar, T, Otgonbayar, O and Boldkhuu, B, 2019. Pit mapping and structural modelling using Adam Tech and Leapfrog Geo Software Solutions, in Proceedings Mining Geology 2019, pp 444449 (The Australasian Institute of Mining and Metallurgy: Melbourne).