I don't really keep track but I think the highest hike up is around 8500 feet in Canada so far, around 8200 in Az. I've been experimenting with 2 element yagi's that are about 6' off of the ground on mountain tops. Seems that the rock has little effect on the antenna. Add soil and things go south real quick. 2 meter contacts from HT to a mobile is regularly 85 km. Furthest is 265 km, HT with EDZ on a mast to a mobile.