Strange area at Roswell NM.

I was browsing around Roswell with google and came across this area.

The thing that caught my eye was the inverted pyamid and when I zoomed the area above it there seems to be a hill that has many paths leading into it from all sides. Anyone know what this may be?

maps.google.com...,+nm&ll=33.190126,-104.467020&spn=0.040199,0.058545&t=k&hl=en

There also appears to be a few structures on the left betwwen the pyramid and hill.

Zoom in on the many paths hill and it looks like the local dirt bike place. The arrow looks like one of those rural airport markers.