Between a rock and a hard place.
If you do not want to move your fence around natural obstacles, such as trees or boulders, incorporate them into the fence. Tahoe Fence can build most styles of fences up to a natural obstruction in the fence line without attaching to the object.
Pictured: Welded-rod utility panels sandwiched with redwood posts and rails with 2-sections cantilevered around trees in West Lake Tahoe (Placer County.)
Dogear wood fencing with 1×6 boards cut over a boulder in Mammoth Lakes (Mono County.)