Definitely a Mexican "bowie" knife, and I'd say a pretty nice one at that. Likely cow horn handle scales and much nicer blade etching than the one I purchased in Oaxaca in 1963. They don't bring a lot of money these days, but there were a lot of makers from the 1930s on, mostly in the state of Oaxaca (pronounced wah-hah-cah) and there are people who collect those made by certain makers. The condition of the one found by Rebel8 is a little lacking do to exposure to the elements, but still a nice find.