Ever wonder what's the most dangerous day to be in a national park? That would be Saturday. And the most dangerous region of the National Park System? That would be the Intermountain Region, home to Glacier, Yellowstone, Grand Teton, Grand Canyon and even Big Bend national parks.

Those factoids are courtesy of the National Park Service's 2007 Search and Rescue report, a detail-chocked document that runs down everything from how search-and-rescue subjects were rescued, what factors led to their predicaments, even how far, in both horizontal and vertical distance, they moved from their original point of misstep.

Here, in no particular order, are some of the details you can glean from this report:

* Number of SAR incidents in the National Park System in 2007: 3,593

* Number of incidents in which the SAR costs exceeded $500: 703

* Number of SARs that involved fatalities: 136

* Number of SARs without injuries or illnesses: 2,566

* Geographic feature (land, lake, ocean, river) most involved in SAR mission: Land, 2,404 missions.

* Age-group most likely the focus of SAR missions: subjects aged 0-12 years old represented 16.46 percent of all SARs. Close behind were those aged 20-29, 15.42 percent.

* Gender of most SAR subjects: Male, 39.77 (although this is questionable, as in 33.19 percent of the cases gender was not listed)

* Length of SAR missions: 97.83 percent of the missions were concluded within 24 hours.

* While park visitors far and away were the target of most SARs (82.20 percent), members of tour groups were the subject in 4.88 percent of the cases, members of outdoor organizations were the subject in 2.26 percent, and National Park Service employees were the subject in 6.27 percent.

* Nearly one-third (31.04 percent) of all SAR subjects were hiking when they got in trouble. The second "most dangerous" activity was swimming (19.18 percent of all SAR missions).

* Most subjects (68 percent) were found within a mile of the location where they became lost/hurt. Just 1.16 percent traveled more than 20 miles.

* The main cause behind an individual needing to be rescued was almost equally split between fatigue or poor physical condition (22.48 percent) and judgment error (22.35 percent).

* Most (13.96 percent) SAR missions were needed on Saturdays, with Sundays (10.72 percent) the second-most dangerous day. Mondays (7.23 percent) and Thursdays (7.17 percent) seemingly were the least dangerous.

* Nearly one-quarter of all SAR missions required a helicopter rescue.

* The Intermountain Region parks reported the most fatalities in 2007, with 49. The Pacific West Region was second, with 39. The Intermountain Region also had the most SAR missions of any region, 1,092. Northeast Region parks stood second in this category, with 983.