REST is a "URL friendly" way to retrieve data (generally in an XML format) over the web. This service lets you acquire near real-time water data from thousands of sites managed or monitored by the USGS across the country. Readings are usually made every 15 minutes and transmitted hourly. Data is currently available since October 1, 2007. Note: certain operational data is typically restricted to 120 days. A number of flexible filters allow you to find data about sites of common interest easily. Call 1-888-275-8747 for questions.