The tumbling value of crude oil has current fuel prices creeping slowly downward, like on Monday afternoon when regular unleaded fell below the $4 mark at the Greencastle Clark station. By Tuesday afternoon, though, prices had returned to $4.19 at five of Greencastle's 10 stations. The cost remains a far cry from what it was in the not-too-distant past. The photo below of the Greencastle McClure station in the late 1990s shows regular unleaded, super unleaded and diesel fuel all under $0.90 per gallon. As of Tuesday afternoon, the average price for a gallon of regular unleaded was $4.09 in Greencastle. It had recently spiked to nearly $4.30 per gallon.