diff --git a/las_manipulation.py b/las_manipulation.py
index 7fc5357..7f3adbf 100644
--- a/las_manipulation.py
+++ b/las_manipulation.py
@@ -387,25 +387,22 @@ def process(yaml_file):
     # Get base name of input las
     las_basename = os.path.splitext(os.path.basename(input_las))[0]
 
-    # Crop to beach boundary
+    # # Crop to beach boundary
     print('Clipping...')
-    las_data = call_lastools('lasclip', input=input_las, output='-stdout',
+    las_clipped_name = os.path.join(tmp_dir, las_basename + '_clipped.las')
+    call_lastools('lasclip', input=input_las, output=las_clipped_name,
                              args=['-poly', initial_crop_poly], verbose=False)
 
     # Classify ground points
     print('Classifying ground...')
-    las_data = call_lastools('lasground_new', input=las_data, output='-stdout',
+    las_classified_name = os.path.join(las_dir, las_basename + '.las')
+    call_lastools('lasground_new', input=las_clipped_name, output=las_classified_name,
                              args=['-step', lasground_step], verbose=False)
 
-    # Save classified point cloud
-    las_name = os.path.join(las_dir, las_basename + '.las')
-    with open (las_name, 'wb') as f:
-        f.write(las_data)
-
     # Interpolate point cloud onto a grid
     print('Interpolating to grid...')
     xyz_name = os.path.join(tmp_dir, las_basename + '.xyz')
-    call_lastools('las2dem', input=las_data, output=xyz_name,
+    call_lastools('las2dem', input=las_classified_name, output=xyz_name,
                   args=['-step', 1], verbose=False)
 
     # Make runup clipping mask from gridded point cloud