Also, please see my YouTube video How To Find The Model Year Of Your Trek Bike.
I bought my Trek 700 used off of craigslist. Supposedly Trek frames have a serial number on them, usually located on the bottom bracket. And with the serial number you are supposed to be able to find the year. But I looked on the BB of my Trek 700, but I could not find a serial number. I even read that it might be hidden under the cable guide, so I removed that. But there was nothing there either. Maybe the higher level Trek’s have serial #’s but the cheaper ones don’t? I dont know.
But I still wanted to know what the model year of my Trek 700. So first I headed over to vintage-trek.com. This is a really cool site!!! Going to the Trek Models By Year page, I found that there was a Trek 700 road bike made in 1983. Mine is not a road bike, it is a hybrid. But they made a “mountain bike” version of the Trek 700 from 1991 to 2001. Now I went to the Trek Brochures page. I was able to browse the brochures from 1991 to 1995. Specific models of Trek bikes come in a very limited number of colors each model year. I went through each brochure looking to see what colors the Trek 700 came in for that year. I quickly found that none of the Trek 700′s came in greem for the years. Unfortunatly, they only had brochures up to 1995. So now I went to bikearchive.com. Here they had tech sheets from 1998 to 2001 for the Trek 700. I went through each of the data sheets until I came to the 2001 tech sheet. It listed several colors, one of which was Rainforest with gold/white decals. Sounded right. I started looking through the rest of the specs. Sure enough, everything matched. So I quickly decided my Trek 700 Multitrack was a 2001 model. Much newer than I had thought. The tech sheet also gives a ton of other cool information.

I also used this method to find the model year of my Trek 1000. It was listed on eBay as probably a 1992, but by going through the brochures, I found it was a 1990 model. The info was all on Vintage-Trek.com.