Russ: An umbrella is a good fallback option if we can't come up with something more permanent.
John G.: The treehouse platform is about 17 feet (20 feet on the low side) above the ground and I'm not sure about the cost/ability to sink pilings that would reach that high. We've sort of reconciled ourselves to losing the treehouse when the tree rots away.
Here's a picture from Saturday after some clearing by the pond builder:
