Code for Portland is throwing a National Day of Civic Hacking event at the end of the month (weekend of the 30th-31st-1st), and mappers are going to be in high demand. More info here: http://www.codeforportland.org/news/2014/05/ndoch-hackathon/.
There are some really awesome projects in the hopper, including a trail data project with Metro. Groups are going to start forming at the Hack Night this Tuesday, so come to that if you can too! All the meet up info is here: http://meetup.com/Code-for-Portland .