rospack can't find package created with catkin_create_package
I'm working through the beginner tutorials using ROS Hydro and I attempted to create my first package by running:
$ catkin_create_pkg beginner_tutorials std_msgs rospy roscpp
This produced no errors and appears to have created the associated files and folders. However, using rospack to find the newly created package doesn't work:
$ rospack find beginner_tutorials
[rospack] Error: stack/package beginner_tutorials not found
What am I missing?