January of this year, though I didn't bust any birds And that was just spots north of the Proving Grounds fyi. I didn't get into the field until the afternoon.

I just looked on Google Earth and found the spot where the hills were crawling....
Turn onto74 West from North 211th Ave (runs parallel to Westside of Proving Grounds)
Go just past N 235th ave (a dirt road on your left that dead-ends into 74), and on your right you'll see a dirt road up into State Lands. Take that up to a fence line on your left. Follow that fence line West until you drop into a tree-lined draw. That's where I parked, walk those arroyos and you should find 'em. Let me know if you do!

There's also a water source, looks like maybe a stock pond, a couple hundred yards past that fence line on the left. IF I recollect, you can drive past the fenceline, it doesn't cross the dirt road, but who knows after all this time.

Good luck!