A nationally recognized regional trail system required a bridge in a remote section that would need to be flown in by helicopter.  Frank Lehman's challenge was staking out specs for the bridge and the abutments at 70.14 feet apart with a bridge that was going to be 70 feet long.  So, essentially the spec only had 14 hundredths of an inch of “slop” in order for that bridge to fit!

If you'd like more information about this project, please take a look at this article: https://www.topconpositioning.com/na/insights/trailblazing-survey-work