You certainly CAN. The data may be online, or you may have to physically go to the office that handles deeds. In my area, data go back to the 1960s, in many cases.
However, if you're looking for comps, the question is whether you SHOULD. In many areas, data on sales of property from, say, 2006 would give an entirely misleading picture of the value of a property. There are plenty of areas around me (Northern Virginia) where houses that sold for $500,000 in 2006 are selling for $225,000 today. Condos that sold for $300,000 in 2006 are selling for $90,000 today. And other areas--more to your point--where properties sold for $400,000 in 2006 and there are no recent sales. No way to tell for sure what those properties are worth.
My suggestion would be to contact a Realtor. Don't just ask for sales. Ask for properties that were listed and didn't sell. Maybe they were withdrawn. Or maybe the owner decided to rent the property instead.
In the example above, of a $400,000 property without recent sales comps, I'd look at all activity. Maybe a few houses were listed last year at $300,000 and didn't sell. That tells you the price is somewhere below $300,000. Maybe a house was listed for sale at $320,000 and for rent at $1,700 and ended up being rented. Again, an indication that $320,000 was too high.
That's what I'd do before relying on sales from three years ago.
Hope that helps.