This is a derivative of a kind of puzzle known as a Nonogram or Griddler. It's a logic puzzle in the form of a grid. The Nonogram is named after Non Ishida (try Googling for "ishida puzzle"). But the hint isn't really necessary since the memo tells you all you need to know.

By the way, for the usual sort of Nonogram, there are solvers available on the Web. You just type in the numbers and they solve the puzzle almost instantly. However, the usual Nonogram is made from a square grid, and this one is hexagonal. Darn.

The numbers on the edge of the grid correspond to the number of consecutive black hexes in each grouping along a row of hexes. By making systematic deductions, the pattern of black hexes can be determined. For example, the lower-left corner must be white, since the 0 next to it indicates no black hexes. The 10 on the top row indicates the leftmost column contains a single group of 10 consecutive black hexes. Since the last hex in the row is known to be white, and there are 11 hexes, the rest must be black. The 1 next to the 0 on the bottom now must refer to the black hex just filled on the left column, so the other hex on that diagonal must be white. Eventually you will get the whole grid, which looks like this:

If you squint at that properly you'll see it says Redstone Dune Trail, which is marked on the park map that one hopes the players picked up when entering Lake Mead National Recreation Area.

Clue author: Walter Smith