<p>^^^ There are perfectly good reasons why someone (a Geology student in particular) might prefer any of the other 3 schools to Dartmouth. Although it is the most socially prestigious and selective of the four, its social life is heavily influenced by fraternities and sororities ([Dartmouth</a> College Greek organizations - Wikipedia, the free encyclopedia](<a href=“http://en.wikipedia.org/wiki/Dartmouth_College_Greek_organizations]Dartmouth”>Dartmouth College fraternities and sororities - Wikipedia)). Some students like this; some don’t. The location is fairly remote. Winters are long and bitterly cold (as they are at Carleton). Then there is the old “animal house”, beer culture reputation. And, it is the only one of these 4 schools that is not a member of the Keck Geology Consortium. </p>
<p>Having spent a year in Northfield years ago, I’m somewhat familiar with Carleton. I only know Dartmouth by reputation. My impression of the two is that Carleton has a more self-consciously intellectual atmosphere (somewhat akin to Reed, Chicago or Swarthmore). Maybe things have changed over the years at Dartmouth though. Whitman and Colorado College are both fine schools, less selective than Carleton and much less so than Dartmouth, but attractive nevertheless. If part of Dartmouth’s attraction is outdoor recreation, Whitman or Colorado have at least as much to offer in this regard. </p>
<p>Colorado College seems to have a strong geology department (though Consolation is right, you’ll be offered a greater number of courses at a larger U). The block plan facilitates field work. Good facilities (including a new LEED-certified science center) and an unparalleled, geologically rich location add to the attraction.
[Geology</a> Department - Colorado College](<a href=“http://www.coloradocollege.edu/dept/GY/facil.asp]Geology”>http://www.coloradocollege.edu/dept/GY/facil.asp)</p>
<p>I have no strong opinion about the use of ED as an admissions chance-boosting stratagem (though that is not its intended purpose). If the OP would be happy to attend any of these 4 schools and wants to please his parents, it may well work to best advantage to play this card on Dartmouth. But if he has reasonable doubts about Dartmouth or any other school, I don’t see the urgency of using ED at all. Without having seen the OP’s stats, it looks like he’s focusing on 4 good schools that share similar features, across a decent range of selectivity (though none of them are safety schools for most people). Put equal effort into each application, don’t take any for granted, and reassess after decisions come in.</p>