I've found wallets/purses in creeks and woods in "vibrant and diverse" parts of town, and one rather off-putting spot I came across was a large concrete slab in the woods that was about 8 inches above the dirt, resting on rocks/rubble. I looked under the slab and saw gobs and gobs of pairs of shoes and something like 5 wallets all mysteriously owned by white folk, with trash, blunt wrappers, 100+ visible 40oz beer bottles laying around the area and a disgusting patch piled with months worth of human feces and plants around it killed by urine. I grabbed the wallets to deposit in a mailbox and got outta there quick before I got culturally enriched by the denizen(s) of that fetid lair too.
In a different state, I was exploring a similar blighted area and found the remnants of what must have been in a stolen purse or wallet but unfortunately nothing personally identifying. I guess they took the ID and credit/debit cards, but left a scatter of Gift Cards in the leaves which I picked up. One was a Kay Jeweler's gift card with 400 bucks on it!
Not sure how many of you do this, but often one sees gift cards in parking lots or in urban creeks (cards traveled down and out storm drains) and since they don't look like money most people leave them alone, but I always grab them and check the balances. More than 1/3 of the time in my experience they have money on them, sometimes a good amount.