For Larch Mountain, Oregon...
If you are hiking the short hike from the parking lot near the top, take the paved path to the far right of the parking lot. The hike is less than a mile to the summit. The summit is very small. It is best to do this early in the morning I think as to not disturnb other hikers. As we were leaving over 100 people were coming up for a short wedding in a very small space.
I was able to get five contacts in a reasonable amount of time including one summit to summit!