diff --git a/sup3r/bias/bias_calc.py b/sup3r/bias/bias_calc.py
index 76f43fced..098c8005c 100644
--- a/sup3r/bias/bias_calc.py
+++ b/sup3r/bias/bias_calc.py
@@ -8,19 +8,17 @@
 import os
 from abc import abstractmethod
 from concurrent.futures import ProcessPoolExecutor, as_completed
-from glob import glob
-from pathlib import Path
 
 import h5py
 import numpy as np
 import pandas as pd
 import rex
-from rex.utilities.fun_utils import get_fun_call_str
 from rex.utilities.bc_utils import (
+    sample_q_invlog,
     sample_q_linear,
     sample_q_log,
-    sample_q_invlog,
 )
+from rex.utilities.fun_utils import get_fun_call_str
 from scipy import stats
 from scipy.ndimage import gaussian_filter
 from scipy.spatial import KDTree
@@ -29,39 +27,11 @@
 from sup3r.preprocessing.data_handling.base import DataHandler
 from sup3r.utilities import VERSION_RECORD, ModuleName
 from sup3r.utilities.cli import BaseCLI
-from sup3r.utilities.utilities import nn_fill_array
+from sup3r.utilities.utilities import expand_paths, nn_fill_array
 
 logger = logging.getLogger(__name__)
 
 
-def _expand_paths(fps):
-    """Expand path(s)
-
-    Parameter
-    ---------
-    fps : str or pathlib.Path or any Sequence of those
-        One or multiple paths to file
-
-    Returns
-    -------
-    list[str]
-        A list of expanded unique and sorted paths as str
-
-    Examples
-    --------
-    >>> _expand_paths("myfile.h5")
-
-    >>> _expand_paths(["myfile.h5", "*.hdf"])
-    """
-    if isinstance(fps, (str, Path)):
-        fps = (fps, )
-
-    out = []
-    for f in fps:
-        out.extend(glob(f))
-    return sorted(set(out))
-
-
 class DataRetrievalBase:
     """Base class to handle data retrieval for the biased data and the
     baseline data
@@ -163,8 +133,8 @@ class to be retrieved from the rex/sup3r library. If a
         self._distance_upper_bound = distance_upper_bound
         self.match_zero_rate = match_zero_rate
 
-        self.base_fps = _expand_paths(self.base_fps)
-        self.bias_fps = _expand_paths(self.bias_fps)
+        self.base_fps = expand_paths(self.base_fps)
+        self.bias_fps = expand_paths(self.bias_fps)
 
         base_sup3r_handler = getattr(sup3r.preprocessing.data_handling,
                                      base_handler, None)
@@ -1224,6 +1194,7 @@ class QuantileDeltaMappingCorrection(DataRetrievalBase):
     :func:`~sup3r.bias.bias_transforms.local_qdm_bc` to actually correct
     a dataset.
     """
+
     def __init__(self,
                  base_fps,
                  bias_fps,
@@ -1308,7 +1279,7 @@ def __init__(self,
 
         self.bias_fut_fps = bias_fut_fps
 
-        self.bias_fut_fps = _expand_paths(self.bias_fut_fps)
+        self.bias_fut_fps = expand_paths(self.bias_fut_fps)
 
         self.bias_fut_dh = self.bias_handler(self.bias_fut_fps,
                                              [self.bias_feature],
diff --git a/sup3r/preprocessing/data_handling/mixin.py b/sup3r/preprocessing/data_handling/mixin.py
index 5c5a69136..091897b33 100644
--- a/sup3r/preprocessing/data_handling/mixin.py
+++ b/sup3r/preprocessing/data_handling/mixin.py
@@ -2,7 +2,6 @@
 @author: bbenton
 """
 
-import glob
 import logging
 import os
 import pickle
@@ -18,6 +17,7 @@
 
 from sup3r.utilities.utilities import (
     estimate_max_workers,
+    expand_paths,
     get_source_type,
     ignore_case_path_fetch,
     uniform_box_sampler,
@@ -644,22 +644,15 @@ def file_paths(self, file_paths):
         ----------
         file_paths : str | list
             A list of files to extract raster data from. Each file must have
-            the same number of timesteps. Can also pass a string with a
-            unix-style file path which will be passed through glob.glob
+            the same number of timesteps. Can also pass a string or list of
+            strings with a unix-style file path which will be passed through
+            glob.glob
         """
-        self._file_paths = file_paths
-        if isinstance(self._file_paths, str):
-            if '*' in file_paths:
-                self._file_paths = glob.glob(self._file_paths)
-            else:
-                self._file_paths = [self._file_paths]
-
+        self._file_paths = expand_paths(file_paths)
         msg = ('No valid files provided to DataHandler. '
                f'Received file_paths={file_paths}. Aborting.')
         assert file_paths is not None and len(self._file_paths) > 0, msg
 
-        self._file_paths = sorted(self._file_paths)
-
     @property
     def ti_workers(self):
         """Get max number of workers for computing time index"""
diff --git a/sup3r/utilities/era_downloader.py b/sup3r/utilities/era_downloader.py
index 455da426e..8606ac769 100644
--- a/sup3r/utilities/era_downloader.py
+++ b/sup3r/utilities/era_downloader.py
@@ -731,7 +731,7 @@ def run_year(cls,
                  area,
                  levels,
                  combined_out_pattern,
-                 combined_yearly_file,
+                 combined_yearly_file=None,
                  interp_out_pattern=None,
                  interp_yearly_file=None,
                  run_interp=True,
@@ -834,10 +834,13 @@ def run_year(cls,
                 logger.info(f'Finished future for year {v["year"]} and month '
                             f'{v["month"]}.')
 
-        cls.make_yearly_file(year, combined_out_pattern, combined_yearly_file)
+            if combined_yearly_file is not None:
+                cls.make_yearly_file(year, combined_out_pattern,
+                                     combined_yearly_file)
 
-        if run_interp:
-            cls.make_yearly_file(year, interp_out_pattern, interp_yearly_file)
+            if run_interp and interp_yearly_file is not None:
+                cls.make_yearly_file(year, interp_out_pattern,
+                                     interp_yearly_file)
 
     @classmethod
     def make_yearly_file(cls, year, file_pattern, yearly_file):
@@ -863,7 +866,7 @@ def make_yearly_file(cls, year, file_pattern, yearly_file):
         ]
 
         if not os.path.exists(yearly_file):
-            with xr.open_mfdataset(files) as res:
+            with xr.open_mfdataset(files, parallel=True) as res:
                 logger.info(f'Combining {files}')
                 os.makedirs(os.path.dirname(yearly_file), exist_ok=True)
                 res.to_netcdf(yearly_file)
diff --git a/sup3r/utilities/regridder.py b/sup3r/utilities/regridder.py
index fa086a230..c50eede76 100644
--- a/sup3r/utilities/regridder.py
+++ b/sup3r/utilities/regridder.py
@@ -199,6 +199,7 @@ def get_all_queries(self, max_workers=None):
         else:
             logger.info('Querying all coordinates in parallel.')
             self._parallel_queries(max_workers=max_workers)
+        logger.info('Finished querying all coordinates.')
 
     def _serial_queries(self):
         """Get indices and distances for all points in target_meta, in
diff --git a/sup3r/utilities/utilities.py b/sup3r/utilities/utilities.py
index b0ac20a62..0479c88f3 100644
--- a/sup3r/utilities/utilities.py
+++ b/sup3r/utilities/utilities.py
@@ -10,6 +10,7 @@
 import string
 import time
 from fnmatch import fnmatch
+from pathlib import Path
 from warnings import warn
 
 import numpy as np
@@ -55,6 +56,34 @@ def __call__(self, fun, *args, **kwargs):
         return out
 
 
+def expand_paths(fps):
+    """Expand path(s)
+
+    Parameter
+    ---------
+    fps : str or pathlib.Path or any Sequence of those
+        One or multiple paths to file
+
+    Returns
+    -------
+    list[str]
+        A list of expanded unique and sorted paths as str
+
+    Examples
+    --------
+    >>> expand_paths("myfile.h5")
+
+    >>> expand_paths(["myfile.h5", "*.hdf"])
+    """
+    if isinstance(fps, (str, Path)):
+        fps = (fps, )
+
+    out = []
+    for f in fps:
+        out.extend(glob(f))
+    return sorted(set(out))
+
+
 def generate_random_string(length):
     """Generate random string with given length. Used for naming temporary
     files to avoid collisions."""