Hi, i copied you picture and had a look around the net.
If you say it was found 40 years ago, it may be a 1906 pikes peak 'so-called dollar', they are collectible. Though there are various medallions also give for hikers, runners etc who i guess race up the mountain at certain events, though those medallions usually depict a runner or hiker of some sort, so i would be thinking your's maybe a 1906 so-called dollar.
What's on the back of the medallion?
Here's some info i found,
1906: Colorado Springs citizens celebrate the 100th anniversary of Zebulon Pike's discovery of Pikes Peak. In addition to many various celebrations held throughout the year, the Pike Centennial Committee commissions the Philadelphia Mint to strike medals to commemorate the event. 10,000 medals the size of half dollars are struck and sold ($1 each for silver, 50 cents each for bronze). Sales were slow, so many were made into watch fobs or pendants.
Official Medals authorized by 59th Congress; designed by C. E. Barber; struck at Philadelphia Mint. Mint records reveal issue limited to 250 Silver proof, 250 Gold-plate, 4,200 gray-oxidized Silver and 6,250 Bronze; sold through local banks and Chamber of Commerce; Bronze for 50 cents, Silver for $1; 65% of all were looped. Some authorities insist these quantities were ones "ordered," that issue actually was smaller. In any event, of total struck, large portion was delivered by Mint apparently too late for sale; they were stored and forgotten for 49 years.
In 1955 these 4,000 pieces were found in basement of old First National Bank Building during demolition. Historical Society of Pike's Peak Region, Inc. directed their sale to help finance 1956 Celebration (no new or additional medals struck for latter event). Again, most were mounted but loops were "expertly removed to make…acceptable to Collectors" and many do defy detection.
Colorado newspapers of 1906 cautioned public to buy "only the genuine authorized medal" as an imitation had appeared on market.
The car depicted on the medallion is also quite similar to the 1906 model K fords at the time:
http://2.bp.blogspot.com/-lR7QhA4Vawg/TVOAsMqpRNI/AAAAAAAAAbM/WBkJH3K_VGA/s1600/06_Ford_K_Rdstr_Red.jpgHere is a link to some examples:
http://www.skyrunner.com/story/pp_medals.htmand here is a link to a So-called dollar collectors site:
http://so-calleddollar.com/DollarSite/DollarPhotos.aspx?category=220&title=Auction%20ArchivesAs for price, there was a 1906 bronze medallion sold for $35 USD, however yours would seem to be a gray-oxide silver medallion, in which they made slight fewer of, so it may be only slightly more valuable assuming it is found to be an actual pike's peak 1906 so-called dollar.
Well i hope that helps!
Kind regards,
Jeremy