Create topography from vertices

Question

I'm very new to Blender and recently I have been trying to model topography I have gathered from USGS lidar surveys. From the data that I have gathered, I have created a series of vertices that represent the topography. The vertices look great in blender but as of right now I do not know how to connect the vertices together to make faces.

This is the code I am using to get each of the coordinates (vertices):

csvfile = open("path/topopoints.csv")
inFile = csv.reader(csvfile, delimiter=',')
vertices = [(float(r[0]), float(r[1]), float(r[2])) for r in inFile]
name = "grid"
mesh = bpy.data.meshes.new( name ) #Create the mesh (inner data)
obj = bpy.data.objects.new( name, mesh ) #Create an object
faces = []
polygons = []
obj.data.from_pydata( vertices, faces, polygons )
bpy.context.collection.objects.link( obj ) #Link the object to the scene

This works well and puts the vertices in the correct position, but I am trying to figure out how to generate the faces (or polygons) required to connect all the vertices of my mesh (To make it look like topography).

Any help would be greatly appreciated and if you have any questions or comments I will be sure to respond quickly.

EDIT: Here is how my scene currently looks. Above image shows starting vertices at bottom right.