In this work, we conducted a GNSS kinematic field survey of a selected forest trail to determine which parts of the trail can be qualitatively positioned with GNSS during different forest growing seasons. We compared different vegetation conditions and the differences in the quality of observations obtained with geodetic and low-cost GNSS receivers. The objective of the task was to determine how vegetation affects the quality of trajectory determination. When processing the observations, we found that better results were obtained with the low-cost ZED-F9P receiver from u-blox than with the Javad Triumph-LSA geodetic receiver. The latter was better able to distinguish between trajectories inside and outside the forest. Future work could improve this work by investigating the usefulness of other low-cost GNSS devices in determining trajectories under difficult conditions. In this way, the quality of the trail data could be determined, which would be the starting point for a higher quality database of mountain trails.