Mystery Photo 48 was taken in a national park. If you can tell us what this thing is and name the national park in which it is located, you will be eligible for our monthly prize drawing.

No Cheating! If we catch you Googling or engaged in other sneakery we will make you write on the whiteboard 100 times:

Arguing that batting average is a very inefficient measure of a batter’s skill, sabermetricians prefer to gauge a batter's ability by on-base percentage (hits plus walks plus hit by pitches divided by at bats plus walks plus hit by pitches plus sacrifice flies, but not sacrifice bunts), slugging percentage (total bases -- one per single, two per double, three per triple, and four per home run – divided by at bats), and more recently, derivatives such as on-base slugging percentage (on-base percentage plus slugging percentage).