I came across this site while out exploring. It’s a field and wetland managed for wildlife habitat. Several paths, perhaps a little over 1/2 mile, have been mowed in the tall grass to allow easy walking around the site to explore, learn, and to watch for wildlife. You can also view the spring which is the headwaters of Curtin Creek.
It can be tricky to reach, since the entrance is at the end of NE 72nd Ave, and 72nd Ave can only be turned onto when going west on NE 78th St.
Curtin Creek Wildlife Habitat 
Curtin Creek Wildlife Habitat 
Curtin Creek Wildlife Habitat
We visited today (4/4/22) but the gate was locked. It was 4;00 p.m. what hours and dsys is this habitat area open to the public?
Sorry, I had missed this question when you posted it some months ago. I believe that at Curtin Springs you can walk the trails at any time (daylight hours), just the parking lot and office are closed outside of regular hours. I have usually parked in the cul-de-sac near the entrance and walked in.