I saw this dragonfly in Cape May, NJ on July 31st, 2010. It is a female.

This one is male. I saw it at Swan Harbor on August 17th, 2012.

These were at Kenilworth Aquatic Gardens in Washington, DC, on August 18th, 2012.

I saw these at Susquehanna State Park on June 23rd, 2013.

These were at Swan Harbor on June 30th, 2013.

I saw these at Susquehanna State Park on July 3rd, 2013.

This one was at Bombay Hook NWR on July 16th, 2013.

I saw many Blue Dashers at Swan Harbor on June 28th, 2014.

This female was at Perryman Park on July 20th, 2014.

I saw this female at Swan Harbor on August 3rd, 2014.

I saw a male and female at Swan Harbor on June 13th, 2015.

These were at Kenilworth Aquatic Gardens in DC on July 10th, 2015.