Limestone Canyon Regional Park

On acces days once a month is ok to hike there, spring season it is awesome, there are miles of trails with native oak trees.

No

You must sign up for available hikes @ let's go outside. Every person wishing to hike must sign up, spaces are limited, many hikes are docent lead but there are occasional 'open days' when registered hikers/bikers/horseback users roam the trails without a docent. Spaces are limited, example there are 2 spaces left for June 21 docent lead as I write

This is nature reserve, managed by the OC Conservancy, after it was put aside by thr Irvine Company; entry is restricted and only allowed on specific days and times. It is as wild as it can be in an urban environment. Check online for more info and to register to the access day. Best time to visit is on early spring after seasonal rains.

I'm certain it is not

No dogs allowed in Limestone. We all need to police ourselves when visiting the outdoors. Even if there isn't a ranger standing there watching.

Big no....

You can only go there for scheduled events. When you sign up for an event there they send you info on where to park for that event.

Yes, at night. There is a culvert at the RV park, and a entire 100 foot wide underpass near the former quarry that allows movement of deer and mountain lions from one side of the 91 freeway to the other side. I am pretty sure I saw a mountain lion early in the morning about 10 years ago at Carbon Canyon regional park near the sequoia grove. Huge paw prints in mud, and scratch marks 10 ft. up a tree. Like a big, big kitty cat. Saw it up on the adjacent hill, the most distinctive thing was the long tail.