A method of operation of a navigation system includes: generating an extraction job including a crawl task based on a location of a point of interest and a web form type of a website for harvesting the point of interest from the website; receiving a heartbeat from a distributed cache for determining when a client device is available to execute the extraction job; generating an assignment schedule of the extraction job based on the heartbeat for distributing the extraction job to the client device to retrieve a location-based field; and receiving the location-based field associated with the point of interest for displaying on a monitor device.