HBase Java API: java.lang.NoClassDefFoundError

I am prototyping a Java/Maven project that needs to directly access HBase. HBase installed successfully and I created tables via shell using examples in the documentation.

I am able to run "mvn package" to build my project, however when trying to run it the HBase class loading always fails. I isolated the problem by simplifying the failing line / exception -

    ClassLoader loader = HBaseConfiguration.class.getClassLoader();

Exception in thread "main" java.lang.NoClassDefFoundError: org.apache.hadoop.hbase.HBaseConfiguration
at com.mycompany.app.App.class$(App.java:26)
at com.mycompany.app.App.main(App.java:26)

This seems wrong since I believe CLASSPATH is set correctly before running the project -

export HADOOP_CLASSPATH=`hadoop classpath`
export HBASE_CLASSPATH=`/opt/mapr/hbase/hbase-0.90.4/bin/hbase classpath`
export CLASSPATH=$HADOOP_CLASSPATH:$HBASE_CLASSPATH
echo $CLASSPATH
java -cp target/my-app-1.0-SNAPSHOT.jar com.mycompany.app.App

Here is the dependency section from my pom.xml

<dependency>  
  <groupId>org.apache.hadoop</groupId>  
  <artifactId>hbase</artifactId>   
  <version>0.90.4</version>   
  <scope>system</scope>   
  <systemPath>/root/.m2/repository/hbase/hbase/0.90.4/hbase-0.90.4.jar</systemPath>    
</dependency>

<dependency>   
  <groupId>org.apache.hadoop</groupId>   
  <artifactId>hadoop-core</artifactId>  
  <version>0.20.2</version>  
  <scope>system</scope>  
  <systemPath>/root/.m2/repository/hadoop/hadoop/0.20.2/hadoop-0.20.2.jar</systemPath>    
</dependency>

Why is my code failing? The dependencies worked at compile time...