INARCH conducted a Common Observing Period Experiment (COPE) over 2022–2024 as a focal network activity to collect a well-documented and described data set of mountain meteorology and hydrology from INARCH basins over the two-year period as the basis for mountain hydrology model intercomparisons. Of the 35 basins monitored 15 contain some glacier cover, and for these basins we use the Open Global Glacier Model (OGGM) to project the glacier evolution for the W5E5v2.0 climate dataset spanning climate scenarios SSPs 119 to 585. This provides a benchmark dataset of how the glacier and meltwater runoff trajectories in these catchments are seen from the perspective of a global/regional glacier model, which will facilitate comparison to how glaciers and their future hydrological contributions are represented in mountain hydrology models. We present this dataset and discuss the regional similarities and differences across the COPE catchments.