I don’t recommend you visit Aracdia Lake. It turns out the lake office entrance is the only free one. When I turned into any other entrance, there was a sign demanding I pay $7 to park and another $3 just to walk around. Bikes are the same price as hiking. Given the crappy facilities, it’s not worth half that much. So I went back to the only free entrance and walked along the shore.
It was heavily covered with giant slabs of red sandstone. I’ll grant you it’s quite lovely. But during warmer weather, you’ll encounter rattlesnakes. I came close enough to one to set off the rattle, but it wasn’t in a position to strike me from under a couple of rocks. 
It sounded rather odd slapping against the sand and echoing from inside a small chamber, so at first I didn’t recognize it. It’s a big mistake that nowhere on the City’s website does it warn of rattlers in the park. If you don’t know how to deal with them, I’d stay away from the park in warm weather.
Undaunted, I then turned upland and walked a section of one of the bike trails (technically multi-use trails). I figured it was unlikely I’d encounter enforcement for the trail fees, but the shock of what they charged was very disappointing. Then again, the City of Edmond is notorious for such things. The government is uniformly upper-middle-class and snotty, slamming users with fees for every privilege; I’m waiting to hear about a charge for breathing the same air they do. They honestly believe that you should pay for the privilege of rattle-snake bites.
I’m not likely to visit Arcadia Lake again, I don’t recommend it to anyone.
Although i understand and share in your disappointment, i still enjoyed the post and the pictures. Yeah, the hoyty toyty rich fokks in our little town started charging families to use the library! Seriously.