Bats inhabit mountainous regions, yet research on species composition and activity across different elevations throughout an entire season remains limited. Globally, studies highlight the strong influence of temperature and water availability on bat species richness, resulting in two distinct patterns: a mid-elevation peak in mountains with dry, arid bases and a linear decrease in mountains with warm, humid bases. Furthermore, in the context of climate change, monitoring bats in mountain environments is a priority, given the decline of many species across Europe. We used Wildlife Acoustics Song Meter Mini Bat detectors, positioned at 300meter elevation intervals, from 700m to 3,100m, within the Gran Paradiso National Park, Italy. The elevational transect was replicated in two valleys, resulting in 18 sampling points. Bat detectors were deployed for two consecutive nights per month from March to November 2023. Recorded sequences were manually identified to species level using Kaleidoscope and BatExplorer software. Each sequence was standardised to a maximum duration of 5 seconds to quantify the number of sequences as a measure of bat activity. Sequences with feeding activity were also counted. Additionally, habitat parameters, such as temperature during the nights, vegetation structure, canopy cover and elevation, were acquired. A total of 34,594 bat sequences were analysed over 280 nights of recordings. Our analysis revealed a peak in bat activity at 1600m in both transects from May to September. This peak is probably driven by a greater abundance of prey, potentially influenced by a greater water availability at these elevations. Using GLMMs we found a significant but not correlated effect of elevation and temperature in shaping bat activity along elevation. Notable, bat presence was detected at 3,100m, but only in August and September, suggesting an expansion of the bat activity to extreme elevations, possibly due to rising temperatures or as evidence of migration.