Wilderness seekers don’t even have to cross a bridge for a salutary dose of nature. This Saturday and Sunday you can meet up at the Presidio Officer’s Club at 10 am for a two hour/ two mile hike along Tennessee Hollow Creek, sourced in the area’s largest watershed. This was one of the original water sources for both the Ohlones and the Spanish and has been carefully restored for the past 15 years. It drains into Crissy Marsh. Free but reservations required.