Road Trip Pic of the day, 7/26: Where and what is this?

Know what this is? Be the first person to e-mail the correct answer--including where it is and its significance--and you will win a prize in the Road Trip picture of the day challenge.

(Credit: Daniel Terdiman/CNET)

Update (Monday, 10:25 a.m.): The answer is Independence Rock, in central Wyoming. It is significance because of a Fourth of July celebration first held there in 1830, and it is (or has been, as many have worn off) covered with names and dates of travelers crossing its path on a journey to a new life in the west.

LARAMIE, Wyo.--During more than a month on Road Trip 2009 across Colorado, Utah, Idaho, Montana and Wyoming, I've seen more than my share of impressive rock formations.

I've even used a couple of them already as Road Trip Picture of the day challenges. Well, I see no reason not to continue that trend, so your task today is to identify this big rock. Tell me what it is, where it is, and what its historical significance is.

If you're the first person to e-mail me (to daniel--dot--terdiman--at--cnet--dot--com) the right answers to all three of those questions, you'll win a prize.

Ever since I began doing these daily challenges, I've been amazed at how quickly some of you have figured out the answers and how--when you haven't personally seen the subject of the picture--you've been able to figure out what it is. So, I'd also love to hear how you arrived at your answer to today's challenge.

Good luck.

Click here for the entire Road Trip 2009 package.

[mydogwas]

Independence Rock, Wyoming, where settlers traveling the Oregon trail carved thier names, still seen to this day.

[regediter]

This is Independence Rock in the Sweetwater River Valley in Wyoming. The western travelers left the eastern gateways in the Spring and made this landmark their goal to reach by the 4th of July. This was so they would cross the mountains into California before the first snows.

[Perry_Clease]

Ayer's Rock, it is in Australia ;)

[krootdude]

i knew someone would say this XD

[Perry_Clease]

"i knew someone would say this XD"

I find the similarity between the two formations to be interesting.

[Daddio2009]

It is a giant pile of fossilized Mesozoic-era moose dung.

[boinky222]

ha, you guys have it all wrong! you're supposed to e-mail Daniel at the address given in the article. don't you read instructions??? :oD

[slroderick]

Independence Rock. Lived in the Eastern part of Wyoming & went by this frequently

[Giggylicious]

I think this is a giant mountain of used rubber tires, but don't know where it is. The mound is covered in burlap to lessen the possibilty of a major mosquito breeding site, as rainwater would cause pooling in the tires if left to the elements. I personally believe the covering is to hide this eyesore, as well.

Repeat 3 times, real fast: RUBBER BABY BUGGY BUMPERS!

[optimisticmomma]

Devii's Monument , Wyoming made famous in the movie Close Encounters of the Third Kind.