Lost bright green pet tree frog with small orange mark near the riverbank and tall grass in Pierre, SD.

I lost my beloved pet green tree frog while I was out taking a walk along the riverbank in Pierre, SD. He escaped from his habitat window while I was cleaning it, and I think he might have hopped off into some tall grass around the area. If anyone happens to find him, he's bright green with a small orange mark on his side and has a very friendly nature. I'm really worried about him!