Gah! Thanks for coming here.
Essentially, all your if-statements have the following structure:
if (scrolled > (($wheresThisAt)+(N * 20))){
$('#salamander-(N + 1)').css('opacity', '1');
So we can comfortably roll that into a loop:
for (var i = 0; i < 35; i++) {
if (scrolled <= ($wheresThisAt + i * 20)) {
break;
}
$("#salamander-" + (i + 1)).css('opacity', '1');
}