It's a little hard for me to tell but if this is indeed on the driver's side front wheel well, this is most likely just oil. The oil filter is just on the other side of the splash guard, and tends to drip oil here when removed for replacement. Keep an eye on oil level, but most likely the person who changed your oil just spilled it everywhere.
Yes it is drivers front wheel well. I didnt' notice any oil spots where I park. I topped off the oil tonight and will check to see if there is any oil on the ground tomorrow.
Most likely the place that performed the oil change was sloppy, and what you see is where oil dripped and wasn't cleaned off all that well.
If the engine oil level is good, and no puddles of oil form under the truck when it's parked, I wouldn't worry about it. Or you could go back and ask them to check things over, and clean up their mess better.