Hi Lynne Appraiser...my name is Chris Courtney and if you are local to Lane County you may have heard of me. This type of valuation is quite complex and largely subject with very little data. Call me for some insight if you like (912-1405 cell). I am State Certified Residential with Pacific Valuation Group and owner of HouseNow.com. I have appraised numerous properties having river frontage, few of which have similar river frontage such as this. I can tell you that a unit of comparison considered among buyers and savvy brokers would consider a price per lineal river frontage foot...and depending on high bank, low bank, slow moving, white water, or other...your opinion of valuation is best achieved by representing comps $/lineal foot of river front. Because you comp pool may be in excess of what lenders like (6-12 months)...you may consider that your subject is quite rare and consequently resilient to general market forces. Sometimes, one buyer DOES make a market. Get my drift ? (no pun intended of course).....hmmmm...check out a sale by Andrea Gramzo north of $500k..search RMLS bare land and improved SFR since it was marketed both ways and included a significant shop & apartment improvement......while I would speak to a range of values per lineal foot that I have recently confirmed...that would be considered an appraisal and this forum is not to be construed as such. Don't forget to confirm water rights either...and valuing water rights is a complex component also that requires competency or at minimum exhaustive confirmation (recorded water rights certificates). You may also be looking to use comparables that sold improved and which require extraction...sometimes using assessor valuation for improvements is most easily defended. Hope that helps! It should.