diff --git a/siphon/catalog.py b/siphon/catalog.py
index 6cb5019a3..b82e5085d 100644
--- a/siphon/catalog.py
+++ b/siphon/catalog.py
@@ -15,10 +15,10 @@
 from .http_util import create_http_session, urlopen
 
 try:
-    from urlparse import urljoin
+    from urlparse import urljoin, urlparse
 except ImportError:
     # Python 3
-    from urllib.parse import urljoin
+    from urllib.parse import urljoin, urlparse
 
 log = logging.getLogger(__name__)
 log.addHandler(logging.StreamHandler())  # Python 2.7 needs a handler set
@@ -56,7 +56,7 @@ def __init__(self, catalog_url):
         """
         # top level server url
         self.catalog_url = catalog_url
-        self.base_tds_url = catalog_url.split('/thredds/')[0]
+        self.base_tds_url = _find_base_tds_url(catalog_url)
 
         session = create_http_session()
 
@@ -277,7 +277,7 @@ def make_access_urls(self, catalog_url, all_services, metadata=None):
                 service_name = metadata["serviceName"]
 
         access_urls = {}
-        server_url = catalog_url.split('/thredds/')[0]
+        server_url = _find_base_tds_url(catalog_url)
 
         found_service = None
         if service_name:
@@ -369,6 +369,19 @@ def __init__(self, service_node):
         self.number_of_subservices = subservices
 
 
+def _find_base_tds_url(catalog_url):
+    """
+    Identify the base URL of the THREDDS server from the catalog URL.
+
+    Will retain URL scheme, host, port and username/password when present.
+    """
+    url_components = urlparse(catalog_url)
+    if url_components.path:
+        return catalog_url.split(url_components.path)[0]
+    else:
+        return catalog_url
+
+
 def _get_latest_cat(catalog_url):
     r"""
     Get the latest dataset catalog from the supplied top level dataset catalog
diff --git a/siphon/tests/fixtures/cat_non_standard_context_path b/siphon/tests/fixtures/cat_non_standard_context_path
new file mode 100644
index 000000000..fe147925e
--- /dev/null
+++ b/siphon/tests/fixtures/cat_non_standard_context_path
@@ -0,0 +1,76 @@
+interactions:
+- request:
+    body: null
+    headers:
+      Accept: ['*/*']
+      Accept-Encoding: ['gzip, deflate']
+      Connection: [keep-alive]
+      User-Agent: [Siphon (0.4.0+17.gb19adc3.dirty)]
+    method: GET
+    uri: http://ereeftds.bom.gov.au/ereefs/tds/catalog/ereef/mwq/P1A/catalog.xml
+  response:
+    body: {string: "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\r\n<catalog xmlns=\"\
+        http://www.unidata.ucar.edu/namespaces/thredds/InvCatalog/v1.0\" xmlns:xlink=\"\
+        http://www.w3.org/1999/xlink\" version=\"1.0.1\">\r\n  <service name=\"nongrid\"\
+        \ serviceType=\"Compound\" base=\"\">\r\n    <service name=\"ncdods\" serviceType=\"\
+        OPENDAP\" base=\"/ereefs/tds/dodsC/\" />\r\n    <service name=\"HTTPServer\"\
+        \ serviceType=\"HTTPServer\" base=\"/ereefs/tds/fileServer/\" />\r\n  </service>\r\
+        \n  <dataset name=\"P1A\" ID=\"mwq/P1A\">\r\n    <metadata inherited=\"true\"\
+        >\r\n      <serviceName>nongrid</serviceName>\r\n      <authority>au.gov.bom</authority>\r\
+        \n      <dataType>GRID</dataType>\r\n      <dataFormat>netCDF</dataFormat>\r\
+        \n      <documentation type=\"rights\">Registered research users only</documentation>\r\
+        \n    </metadata>\r\n    <dataset name=\"A20020101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20020101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20020101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">94.89</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T20:51:38Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20030101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20030101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20030101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">97.71</dataSize>\r\n      <date type=\"modified\">2014-03-09T21:12:03Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20040101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20040101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20040101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">98.36</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T12:39:31Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20050101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20050101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20050101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">97.27</dataSize>\r\n      <date type=\"modified\">2014-03-09T12:39:52Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20060101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20060101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20060101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">98.44</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T12:43:41Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20070101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20070101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20070101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">97.62</dataSize>\r\n      <date type=\"modified\">2014-03-09T12:43:09Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20080101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20080101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20080101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">98.55</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T12:44:09Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20090101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20090101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20090101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">97.67</dataSize>\r\n      <date type=\"modified\">2014-03-09T12:44:10Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20100101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20100101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20100101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">97.26</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T12:44:32Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20110101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20110101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20110101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">98.59</dataSize>\r\n      <date type=\"modified\">2014-03-09T12:42:33Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20120101.P1A.ANN_MIM_RMP.nc\" ID=\"\
+        mwq/P1A/A20120101.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20120101.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">98.09</dataSize>\r\n      <date type=\"\
+        modified\">2014-03-09T12:40:15Z</date>\r\n    </dataset>\r\n    <dataset name=\"\
+        A20130101.P1A.ANN_MIM_RMP.nc\" ID=\"mwq/P1A/A20130101.P1A.ANN_MIM_RMP.nc\"\
+        \ urlPath=\"ereef/mwq/P1A/A20130101.P1A.ANN_MIM_RMP.nc\">\r\n      <dataSize\
+        \ units=\"Mbytes\">98.19</dataSize>\r\n      <date type=\"modified\">2014-03-09T12:42:53Z</date>\r\
+        \n    </dataset>\r\n    <dataset name=\"A20140101.316.P1A.ANN_MIM_RMP.nc\"\
+        \ ID=\"mwq/P1A/A20140101.316.P1A.ANN_MIM_RMP.nc\" urlPath=\"ereef/mwq/P1A/A20140101.316.P1A.ANN_MIM_RMP.nc\"\
+        >\r\n      <dataSize units=\"Mbytes\">100.6</dataSize>\r\n      <date type=\"\
+        modified\">2015-01-06T01:05:32Z</date>\r\n    </dataset>\r\n  </dataset>\r\
+        \n</catalog>\r\n"}
+    headers:
+      Connection: [close]
+      Content-Language: [en-US]
+      Content-Type: [application/xml;charset=UTF-8]
+      Date: ['Fri, 09 Sep 2016 00:24:21 GMT']
+      Server: [Apache-Coyote/1.1]
+    status: {code: 200, message: OK}
+version: 1
diff --git a/siphon/tests/test_catalog.py b/siphon/tests/test_catalog.py
index c5cac44e9..2e2050869 100644
--- a/siphon/tests/test_catalog.py
+++ b/siphon/tests/test_catalog.py
@@ -124,3 +124,14 @@ def test_catalog_ref_order():
     assert list(cat.catalog_refs) == ['Forecast Model Data', 'Forecast Products and Analyses',
                                       'Observation Data', 'Radar Data', 'Satellite Data',
                                       'Unidata case studies']
+
+
+@recorder.use_cassette('cat_non_standard_context_path')
+def test_non_standard_context_path():
+    'Test accessing TDS with non-standard Context Path'
+    url = 'http://ereeftds.bom.gov.au/ereefs/tds/catalog/ereef/mwq/P1A/catalog.xml'
+    cat = TDSCatalog(url)
+    ds = cat.datasets['A20020101.P1A.ANN_MIM_RMP.nc']
+    expected = ('http://ereeftds.bom.gov.au/ereefs/tds/dodsC/ereef/mwq/'
+                'P1A/A20020101.P1A.ANN_MIM_RMP.nc')
+    assert ds.access_urls['OPENDAP'] == expected