Lost Beagle-Coonhound in Southwestway Park

My dog is an 8 year old beagle-coonhound mix, 50 pounds, tri-colored, with brown and black speckling. Female, very friendly. We were in Southwestway Park walking and I thought I was going to trip, so let go of her leash to catch myself. After I let it go, she took off and I couldn’t catch up. I kept looking for her until it got too dark. She was barking at 10:15 when I decided to leave because I was too afraid to search alone in the dark. I came back a few hours later, slept in the my car in the parking lot, so my car would be parked there if she came back to the trail head. I looked at dawn that day as well and many times since and now luck.