The first thing we see of Sam is his dream of visiting Jess's grave, which may or may not actually be in Palo Alto where his brain placed it. In his brain he calls her Jess and angsts that he should have protected her and told her the truth, his dream ends with like Carrie with Jess's hand reaching up from her grave to grasp him. Sam guilt-trips himself so hard that I think he might be my Jewish grandmother. And as is the standard op for The WB the leading men must feel guilt at all times, therefor if it rains any time in the near future you can bet on Sam finding a way to convince himself that if he had only sung the "rain, rain, go away" song then it would be bright and sunny out.
When Sam wakes up from his nightmare he shrugs off Dean's questions, a literally silent throw-back to Dean's infamous line in the pilot of "no chick-flick moments." Sam thanks Dean for his inquiry but kindly tells him to bugger off. Dean does not seem especially perturbed by this which leads me to believe that this is how the boys were raised, which would make sense with them having a Marine father, emotions are only good when someone's about to die, in all other cases you should suck it up and stick it away.
This episode is really a big point for Sam's sheer Nerdishness. He either knows off the top of his head or, more likely, has read up rather extensively about Blackwater Ridge and knows a good deal about it going in, he also does some pretty damn good research into previous "grizzly" attacks and even manges to find the lone survivor. Sam also managed to identify the "attacker" as a Wendigo from his memory alone (If we don't see it it didn't happen so I discount him searching through th journal while Dean was taking a piss during the commercial break or something) and then proved it to Dean by pointing out the entry in the journal and reciting it's chief characteristics. This leads me to think that in college Sam was the kid who sold his notes and charged the other students for him to do their research for him, hell I wouldn't put it past him to be able to cite the California Rules of Evidence from memory. He really would've/will make a great lawyer some day.
This is also one of Sam's big bitchy episodes, he has every right to act like a bitch but it's still fun to watch and take note of. At first Sam didn't want to talk to Haley (Tommy's sister) at all, he wanted to find Dad and leave. He had little to no interest in finding Tommy or figuring out what had happened. This is where everyone screams "Sam you selfish little bastard!" at the screen. But really it's understandable the way Sam reacts; Jess died somewhere around a week ago. One. Week. I'm honestly surprised he isn't crying in the backseat this whole episode.
I'm gonna jump forward a bit into the episode to Sam complain that he doesn't want to "babysit" Haley in Blackwater Ridge, it's another bitchy moment for him but it's also a very Winchester moment. I think this was less about not wanting Haley there and more about not wanting any innocents there because they would both be in undue danger and would hold him and Dean back. Sam's protectiveness of others, innocents and Dean, is featured a lot in this episode. Don't believe me?
When the guide, Roy, grabbed the back of Dean's shirt and hauled him back (before we knew it was to avoid a bear trap) Sam took a step forward. He was ready to pounce on Roy if Roy made the wrong move.
When Roy ran off on his own after the "thing" Sam told him not to go off by himself and herded everyone else after him.
When Haley was yelling for her brother, Tommy, Sam told her to be quiet, not to yell.
After they were all lured away Sam was the one who ordered everyone back to the safety of the camp.
Sam told everyone, Haley, her younger brother, Ben, and Roy, to leave and said he shouldn't have let them come.
When the younger brother, Ben, fell Sam went back for him even though it would've been easier to just keep running and leave the boy to stand back up on his own.
After missing hitting the Wendigo Sam puts himself directly in front of Haley, Tommy, and Ben. Right in immediate danger and as the 1-pin in Wendigo bowling. That means that if/when it charged forward it would get him first, and I have no doubt in my mind that he would've tried to fight it off and screamed for them to run if it had come to that. Lucky for everyone Pyro!Dean came to the rescue and Sam lived to Emo another day.
Sam seems to still be grasping his hands onto normal in this episode, trying to be like everyone else. I say this because when Sam told Dean he thought it was a Wendigo he did it after asking Dean to step away from the campfire, out of sight and sound of everyone else. I also can't forget Sam telling Roy that "it" would hunt him down and eat him. Or the fact that after Roy called Sam crazy Sam got halfway through "asking" if he had ever hunted a Wendigo when Dean shoved him away.
While Dean was putting up the Anasazi symbols around the camp for protection Sam was sitting just off of the campfire, away from everyone else and brooding. He was brooding because John wasn't there. Sam wanted to take everyone back to town and leave to go find Dad, he didn't really want to hunt the Wendigo or what looked like anything else for that matter. Even while Dean wanted to hunt down anything and everything Sam only wanted to find Dad and "Jessica's killer." Which is completely understandable. I've said it before and I'll say it again: Sam is Spiderman. He understands that people out there need to be saved and he knows that they can't do it on their own but he resents having to be the one to do it.
I think this is pretty good for two hours, don't you think?