Hi all! Looking for an outdoor park to host at 1,000+ person event with A/V + activations in Houston, Texas, any suggestions?

Following Carter's Houston question... I'm helping a colleague find a retreat space in the Houston area (5 C-suite folks for one weekend). She doesn't want a corporate space or standard hotel, and wants it to have some sort of access to nature. Their budget is about $600/day. We're finding LOTS of religious-leaning retreat spaces & hotels in my search but nothing that fits her requirements. Any recs?