It's no secret that the public's desire to head to the National Park System is creating logjams and congestion. So it should be no surprise that Mount Rainier National Park in Washington state is the latest unit of the system to consider implementing a timed-entry system for visitors during the busiest months of the year.

While in the past fiscal year the National Park Service has spent Great American Outdoors Act funds on backlogged maintenance projects at parks as diverse as San Juan National Park Historic Site, Colonial National Historical Park, and Fort Vancouver National Historic Site, as well as Theodore Roosevelt, Yellowstone, Grand Canyon, and Yosemite national parks, some Republicans in the U.S. House of Representatives are concerned about "dubious multi-million-dollar investments in urban liberal cities" while smaller parks "have struggled to compete for funding."

Discovery of hydrothermal systems on the ocean floor in the late 1970s is regarded as one of the greatest scientific discoveries of the 20th century and has implications for the flux of chemicals and heat into the oceans, the formation of some mineral deposits, and the origin of life. Over the last 50 years, deep-ocean hydrothermal vents have been found along plate boundaries throughout the oceans of the world.

Combine your visit to Gettysburg National Military Park this summer with a stop at the headquarters General Robert E. Lee used during the Battle of Gettysburg.