diff --git a/.github/.OwlBot.lock.yaml b/.github/.OwlBot.lock.yaml
index e2b39f94..cb06536d 100644
--- a/.github/.OwlBot.lock.yaml
+++ b/.github/.OwlBot.lock.yaml
@@ -1,3 +1,3 @@
 docker:
   image: gcr.io/repo-automation-bots/owlbot-python:latest
-  digest: sha256:99d90d097e4a4710cc8658ee0b5b963f4426d0e424819787c3ac1405c9a26719
+  digest: sha256:5ff7446edeaede81c3ed58b23a4e76a5403fba1350ce28478045657303b6479d
diff --git a/.kokoro/docker/docs/Dockerfile b/.kokoro/docker/docs/Dockerfile
index 412b0b56..4e1b1fb8 100644
--- a/.kokoro/docker/docs/Dockerfile
+++ b/.kokoro/docker/docs/Dockerfile
@@ -40,6 +40,7 @@ RUN apt-get update \
     libssl-dev \
     libsqlite3-dev \
     portaudio19-dev \
+    python3-distutils \
     redis-server \
     software-properties-common \
     ssh \
@@ -59,40 +60,8 @@ RUN apt-get update \
   && rm -rf /var/lib/apt/lists/* \
   && rm -f /var/cache/apt/archives/*.deb
 
-
-COPY fetch_gpg_keys.sh /tmp
-# Install the desired versions of Python.
-RUN set -ex \
-    && export GNUPGHOME="$(mktemp -d)" \
-    && echo "disable-ipv6" >> "${GNUPGHOME}/dirmngr.conf" \
-    && /tmp/fetch_gpg_keys.sh \
-    && for PYTHON_VERSION in 3.7.8 3.8.5; do \
-        wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz" \
-        && wget --no-check-certificate -O python-${PYTHON_VERSION}.tar.xz.asc "https://www.python.org/ftp/python/${PYTHON_VERSION%%[a-z]*}/Python-$PYTHON_VERSION.tar.xz.asc" \
-        && gpg --batch --verify python-${PYTHON_VERSION}.tar.xz.asc python-${PYTHON_VERSION}.tar.xz \
-        && rm -r python-${PYTHON_VERSION}.tar.xz.asc \
-        && mkdir -p /usr/src/python-${PYTHON_VERSION} \
-        && tar -xJC /usr/src/python-${PYTHON_VERSION} --strip-components=1 -f python-${PYTHON_VERSION}.tar.xz \
-        && rm python-${PYTHON_VERSION}.tar.xz \
-        && cd /usr/src/python-${PYTHON_VERSION} \
-        && ./configure \
-            --enable-shared \
-            # This works only on Python 2.7 and throws a warning on every other
-            # version, but seems otherwise harmless.
-            --enable-unicode=ucs4 \
-            --with-system-ffi \
-            --without-ensurepip \
-        && make -j$(nproc) \
-        && make install \
-        && ldconfig \
-  ; done \
-  && rm -rf "${GNUPGHOME}" \
-  && rm -rf /usr/src/python* \
-  && rm -rf ~/.cache/
-
 RUN wget -O /tmp/get-pip.py 'https://bootstrap.pypa.io/get-pip.py' \
-  && python3.7 /tmp/get-pip.py \
   && python3.8 /tmp/get-pip.py \
   && rm /tmp/get-pip.py
 
-CMD ["python3.7"]
+CMD ["python3.8"]
diff --git a/.kokoro/docker/docs/fetch_gpg_keys.sh b/.kokoro/docker/docs/fetch_gpg_keys.sh
deleted file mode 100755
index d653dd86..00000000
--- a/.kokoro/docker/docs/fetch_gpg_keys.sh
+++ /dev/null
@@ -1,45 +0,0 @@
-#!/bin/bash
-# Copyright 2020 Google LLC
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#      http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-# A script to fetch gpg keys with retry.
-# Avoid jinja parsing the file.
-# 
-
-function retry {
-    if [[ "${#}" -le 1 ]]; then
-	echo "Usage: ${0} retry_count commands.."
-	exit 1
-    fi
-    local retries=${1}
-    local command="${@:2}"
-    until [[ "${retries}" -le 0 ]]; do
-	$command && return 0
-	if [[ $? -ne 0 ]]; then
-	    echo "command failed, retrying"
-	    ((retries--))
-	fi
-    done
-    return 1
-}
-
-# 3.6.9, 3.7.5 (Ned Deily)
-retry 3 gpg --keyserver ha.pool.sks-keyservers.net --recv-keys \
-      0D96DF4D4110E5C43FBFB17F2D347EA6AA65421D
-
-# 3.8.0 (Łukasz Langa)
-retry 3 gpg --keyserver ha.pool.sks-keyservers.net --recv-keys \
-      E3FF2839C048B25C084DEBE9B26995E310250568
-
-# 
diff --git a/.kokoro/test-samples-impl.sh b/.kokoro/test-samples-impl.sh
index cf5de74c..311a8d54 100755
--- a/.kokoro/test-samples-impl.sh
+++ b/.kokoro/test-samples-impl.sh
@@ -20,9 +20,9 @@ set -eo pipefail
 # Enables `**` to include files nested inside sub-folders
 shopt -s globstar
 
-# Exit early if samples directory doesn't exist
-if [ ! -d "./samples" ]; then
-  echo "No tests run. `./samples` not found"
+# Exit early if samples don't exist
+if ! find samples -name 'requirements.txt' | grep -q .; then
+  echo "No tests run. './samples/**/requirements.txt' not found"
   exit 0
 fi
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 90b45ce6..35bd37da 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,18 @@
 
 [1]: https://pypi.org/project/google-cloud-bigquery-storage/#history
 
+### [2.6.1](https://www.github.com/googleapis/python-bigquery-storage/compare/v2.6.0...v2.6.1) (2021-07-20)
+
+
+### Bug Fixes
+
+* **deps:** pin 'google-{api,cloud}-core', 'google-auth' to allow 2.x versions ([#240](https://www.github.com/googleapis/python-bigquery-storage/issues/240)) ([8f848e1](https://www.github.com/googleapis/python-bigquery-storage/commit/8f848e18379085160492cdd2d12dc8de50a46c8e))
+
+
+### Documentation
+
+* pandas DataFrame samples are more standalone ([#224](https://www.github.com/googleapis/python-bigquery-storage/issues/224)) ([4026997](https://www.github.com/googleapis/python-bigquery-storage/commit/4026997d7a286b63ed2b969c0bd49de59635326d))
+
 ## [2.6.0](https://www.github.com/googleapis/python-bigquery-storage/compare/v2.5.0...v2.6.0) (2021-07-09)
 
 
diff --git a/samples/conftest.py b/samples/conftest.py
new file mode 100644
index 00000000..92068ef5
--- /dev/null
+++ b/samples/conftest.py
@@ -0,0 +1,22 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+import os
+
+import pytest
+
+
+@pytest.fixture(scope="session")
+def project_id():
+    return os.environ["GOOGLE_CLOUD_PROJECT"]
diff --git a/samples/quickstart/quickstart_test.py b/samples/quickstart/quickstart_test.py
index 23f3c350..8e1e0dfd 100644
--- a/samples/quickstart/quickstart_test.py
+++ b/samples/quickstart/quickstart_test.py
@@ -13,9 +13,6 @@
 # limitations under the License.
 
 import datetime
-import os
-
-import pytest
 
 from . import quickstart
 
@@ -27,11 +24,6 @@ def now_millis():
     )
 
 
-@pytest.fixture()
-def project_id():
-    return os.environ["GOOGLE_CLOUD_PROJECT"]
-
-
 def test_quickstart_wo_snapshot(capsys, project_id):
     quickstart.main(project_id)
     out, _ = capsys.readouterr()
diff --git a/samples/quickstart/requirements.txt b/samples/quickstart/requirements.txt
index 9eddd046..ca069335 100644
--- a/samples/quickstart/requirements.txt
+++ b/samples/quickstart/requirements.txt
@@ -1,2 +1,2 @@
 fastavro
-google-cloud-bigquery-storage==2.5.0
+google-cloud-bigquery-storage==2.6.0
diff --git a/samples/to_dataframe/read_query_results.py b/samples/to_dataframe/read_query_results.py
new file mode 100644
index 00000000..45bae1ea
--- /dev/null
+++ b/samples/to_dataframe/read_query_results.py
@@ -0,0 +1,47 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def read_query_results():
+    # [START bigquerystorage_pandas_tutorial_read_query_results]
+    from google.cloud import bigquery
+
+    bqclient = bigquery.Client()
+
+    # Download query results.
+    query_string = """
+    SELECT
+    CONCAT(
+        'https://stackoverflow.com/questions/',
+        CAST(id as STRING)) as url,
+    view_count
+    FROM `bigquery-public-data.stackoverflow.posts_questions`
+    WHERE tags like '%google-bigquery%'
+    ORDER BY view_count DESC
+    """
+
+    dataframe = (
+        bqclient.query(query_string)
+        .result()
+        .to_dataframe(
+            # Optionally, explicitly request to use the BigQuery Storage API. As of
+            # google-cloud-bigquery version 1.26.0 and above, the BigQuery Storage
+            # API is used by default.
+            create_bqstorage_client=True,
+        )
+    )
+    print(dataframe.head())
+    # [END bigquerystorage_pandas_tutorial_read_query_results]
+
+    return dataframe
diff --git a/samples/to_dataframe/read_query_results_test.py b/samples/to_dataframe/read_query_results_test.py
new file mode 100644
index 00000000..55b55a08
--- /dev/null
+++ b/samples/to_dataframe/read_query_results_test.py
@@ -0,0 +1,21 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import read_query_results
+
+
+def test_read_query_results(capsys):
+    read_query_results.read_query_results()
+    out, _ = capsys.readouterr()
+    assert "stackoverflow" in out
diff --git a/samples/to_dataframe/read_table_bigquery.py b/samples/to_dataframe/read_table_bigquery.py
new file mode 100644
index 00000000..82d8879b
--- /dev/null
+++ b/samples/to_dataframe/read_table_bigquery.py
@@ -0,0 +1,42 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def read_table():
+    # [START bigquerystorage_pandas_tutorial_read_table]
+    from google.cloud import bigquery
+
+    bqclient = bigquery.Client()
+
+    # Download a table.
+    table = bigquery.TableReference.from_string(
+        "bigquery-public-data.utility_us.country_code_iso"
+    )
+    rows = bqclient.list_rows(
+        table,
+        selected_fields=[
+            bigquery.SchemaField("country_name", "STRING"),
+            bigquery.SchemaField("fips_code", "STRING"),
+        ],
+    )
+    dataframe = rows.to_dataframe(
+        # Optionally, explicitly request to use the BigQuery Storage API. As of
+        # google-cloud-bigquery version 1.26.0 and above, the BigQuery Storage
+        # API is used by default.
+        create_bqstorage_client=True,
+    )
+    print(dataframe.head())
+    # [END bigquerystorage_pandas_tutorial_read_table]
+
+    return dataframe
diff --git a/samples/to_dataframe/read_table_bigquery_test.py b/samples/to_dataframe/read_table_bigquery_test.py
new file mode 100644
index 00000000..c8301857
--- /dev/null
+++ b/samples/to_dataframe/read_table_bigquery_test.py
@@ -0,0 +1,21 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import read_table_bigquery
+
+
+def test_read_table(capsys):
+    read_table_bigquery.read_table()
+    out, _ = capsys.readouterr()
+    assert "country_name" in out
diff --git a/samples/to_dataframe/read_table_bqstorage.py b/samples/to_dataframe/read_table_bqstorage.py
new file mode 100644
index 00000000..0a3ae777
--- /dev/null
+++ b/samples/to_dataframe/read_table_bqstorage.py
@@ -0,0 +1,69 @@
+# Copyright 2019 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+def read_table(your_project_id):
+    original_your_project_id = your_project_id
+    # [START bigquerystorage_pandas_tutorial_read_session]
+    your_project_id = "project-for-read-session"
+    # [END bigquerystorage_pandas_tutorial_read_session]
+    your_project_id = original_your_project_id
+
+    # [START bigquerystorage_pandas_tutorial_read_session]
+    from google.cloud import bigquery_storage
+    from google.cloud.bigquery_storage import types
+    import pandas
+
+    bqstorageclient = bigquery_storage.BigQueryReadClient()
+
+    project_id = "bigquery-public-data"
+    dataset_id = "new_york_trees"
+    table_id = "tree_species"
+    table = f"projects/{project_id}/datasets/{dataset_id}/tables/{table_id}"
+
+    # Select columns to read with read options. If no read options are
+    # specified, the whole table is read.
+    read_options = types.ReadSession.TableReadOptions(
+        selected_fields=["species_common_name", "fall_color"]
+    )
+
+    parent = "projects/{}".format(your_project_id)
+
+    requested_session = types.ReadSession(
+        table=table,
+        # Avro is also supported, but the Arrow data format is optimized to
+        # work well with column-oriented data structures such as pandas
+        # DataFrames.
+        data_format=types.DataFormat.ARROW,
+        read_options=read_options,
+    )
+    read_session = bqstorageclient.create_read_session(
+        parent=parent, read_session=requested_session, max_stream_count=1,
+    )
+
+    # This example reads from only a single stream. Read from multiple streams
+    # to fetch data faster. Note that the session may not contain any streams
+    # if there are no rows to read.
+    stream = read_session.streams[0]
+    reader = bqstorageclient.read_rows(stream.name)
+
+    # Parse all Arrow blocks and create a dataframe.
+    frames = []
+    for message in reader.rows().pages:
+        frames.append(message.to_dataframe())
+    dataframe = pandas.concat(frames)
+    print(dataframe.head())
+    # [END bigquerystorage_pandas_tutorial_read_session]
+
+    return dataframe
diff --git a/samples/to_dataframe/read_table_bqstorage_test.py b/samples/to_dataframe/read_table_bqstorage_test.py
new file mode 100644
index 00000000..cc093078
--- /dev/null
+++ b/samples/to_dataframe/read_table_bqstorage_test.py
@@ -0,0 +1,21 @@
+# Copyright 2021 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from . import read_table_bqstorage
+
+
+def test_read_table(capsys, project_id):
+    read_table_bqstorage.read_table(your_project_id=project_id)
+    out, _ = capsys.readouterr()
+    assert "species_common_name" in out
diff --git a/samples/to_dataframe/requirements.txt b/samples/to_dataframe/requirements.txt
index 45aeaa2f..142d4942 100644
--- a/samples/to_dataframe/requirements.txt
+++ b/samples/to_dataframe/requirements.txt
@@ -1,8 +1,8 @@
-google-auth==1.32.1
-google-cloud-bigquery-storage==2.5.0
-google-cloud-bigquery==2.20.0
+google-auth==1.33.0
+google-cloud-bigquery-storage==2.6.0
+google-cloud-bigquery==2.21.0
 pyarrow==4.0.1
-ipython==7.10.2; python_version > '3.0'
-ipython==5.9.0; python_version < '3.0'
-pandas==0.25.3; python_version > '3.0'
-pandas==0.24.2; python_version < '3.0'
+ipython==7.24.0; python_version > '3.6'
+ipython==7.16.1; python_version <= '3.6'
+pandas==1.2.5; python_version > '3.6'
+pandas==1.1.5; python_version <= '3.6'
diff --git a/setup.py b/setup.py
index 59c70ba2..b09e3233 100644
--- a/setup.py
+++ b/setup.py
@@ -21,10 +21,13 @@
 
 name = "google-cloud-bigquery-storage"
 description = "BigQuery Storage API API client library"
-version = "2.6.0"
+version = "2.6.1"
 release_status = "Development Status :: 5 - Production/Stable"
 dependencies = [
-    "google-api-core[grpc] >= 1.26.0, < 2.0.0dev",
+    # NOTE: Maintainers, please do not require google-api-core>=2.x.x
+    # Until this issue is closed
+    # https://github.com/googleapis/google-cloud-python/issues/10566
+    "google-api-core[grpc] >= 1.26.0, <3.0.0dev",
     "proto-plus >= 1.4.0",
     "packaging >= 14.3",
     "libcst >= 0.2.5",