The Hot Spring:
Terwilliger Hot Springs (aka Cougar due to the proximity to Cougar Reservoir) consists of a series of five large pools cascading down a forested valley. The spring emerges out of a small cave (barely big enough for one person to get a little steam bath) at 116 degrees Fahrenheit and flows into the upper and hottest pool. Each volunteer built pool fits about 8-12 people and has a granite slab bottom with rock and log walls. The pools are few degrees different varying from 108 at the top to 95 at the bottom and there is a little cold creek that fills a bucket to use as a cold shower. Pathways and stairs have been built around and between the pools. Above the pools is a changing area with a covered bench and hooks to hang your clothing. You can generally reach the springs all year round however in the winter the spring may flow colder, and with the addition of snow melt even the upper pool can be too cold.
Many people consider Cougar to be the best hot spring they have ever visited but despite how wonderful these hot springs sound they are our least favorite hot spring. We actually hate this spring and discourage anyone from spending time here. This is because of the highly seedy nature of the place, and the large presence of police. It is an example of what can happen when a hot spring becomes a party spot. The popularity has made it so vandalism is very common in the parking area, and violence is not uncommon. Also the police frequent the parking lot with a drug dog and will wait all day to search the vehicles that the dog smells something in.
There are also many regulations! You can not park or camp within two miles of the trail head to the springs. It is closed at night and is patrolled a lot with a very big fine if caught parking within the restricted area. A 5 dollar daily use fee for every person is also required and collected at a kiosk at the trail head (this was burned down last time we were there). No alcohol permitted at the spring either however you can be nude but not within the roads visibility. With all these restrictions and the danger of your car getting broken into or searched while soaking, we have decided not to soak here anymore.
Cougar Hot Springs does not have a long history due to its remoteness. It became popular almost immediately after the Cougar Reservoir was built and the paved road that goes within 0.3 miles of the springs. From the 60's through the 90's Terwilliger was a party destination with a tent city rumored to have up to 1000 semi-permanent residents in the forest surrounding it . The partying became too much for the Forest Service in 1998 after a man was killed in 1996 because of a disagreement over late night loud music, and the 1997 Rainbow Gathering nearby which increased the numbers of visitors. Several meetings were held to figure out what to do with the springs and that is when it was closed at night and a fee was implemented to help pay for maintenance. This is also when Friends of Cougar Hot Springs (now part of hoodoo) was formed to work with the Forest Service. So I guess these efforts have helped temper the seedy nature making the springs safer than in years past, but it has also brought a stronger police presence.