That would be enough for a wall. But not enough to build it. A logistics issue. A concrete wall would take a lot of gravel and water. And you would need staging areas.
I don't know the lay of the land down there. So resources like gravel and water become highly relevant. Especially over the distance involved. Identification and access to areas that have one or both would necessitate use of much more land than a 60-foot strip.
@Smokin Joe
Likely what materials could be sourced locally would be purchased from contractors or suppliers there, or mined locally, on federal land, if need be. While that would take more than the Roosevelt Reservation (Teddy, not FDR), that resource development in terms of aggregate and other materials, and access road, could either fit (the road would, and would be needed to patrol the wall and for access), or be developed on private or even public land. That would mean a lot of trucking, much the same as any road project, only this one would have an additional wall on the south side. Since part of that, at least, would consist of steel slats, those materials would have to be shipped in, likely by truck.
Considering we are the nation who built the transcontinental railroad, the Trans Alaska pipeline, and the Panama Canal, among other projects, I'd say it is do-able, but the design of the foundation, and the wall itself would have to adapt to the substrate. The Dems hate the idea because not only would it provide (even more) employment, but a project of that magnitude could be a boost to a lot of red state economies. Plus, that'd be 5 billion they didn't get to skim.