Orange paperback Tucson hiking guide

I found this orange paperback Tucson hiking guide this afternoon around 3:15pm on the sidewalk outside the Rialto Theatre on Congress Street. It's a 6-by-9 inch paperback with a bright cactus illustration and the title 'Pocket Tucson Trails'; there’s a folded city map tucked inside and a blue ink note on the inside front cover reading 'Marta'. The pages are a bit dog-eared and there's a faint coffee stain on the back cover, but otherwise it's in decent shape. I know someone who loves Tucson's trails would want this back; if you recognize these clues, it's probably yours.