Oil filter?

I have just purchased a 1998 blazer (the s10 size). I was changing the oil and i can not find the oil filter, i purchased the filter that the books say goes in, however after searching for 45 minutes i still cannot locate the filter in the truck. It has the 4.3 and it is 4X4, i located what appears to be the place it would go but there is just a plate there and not enough clearance for a filter to fit. Anyone have any input?Oil filter?
is there a removable gaurd under the vehicle with a space to remove a small protion of the the gaurd? if so and to the best of my knoledge remove that portion and the gaurd and the oil filter should be there on the other side.Oil filter?
The previous owner might have removed the oil filter to improve gas mileage.
Are there hoses coming out of that plate? It may have a remote-mount oil filter. Follow the hoses. Some older Blazers have the oil filter in the left front fender well.