Observation Methods 



Modified movie cameras (fig. 4) triggered by infrared 

 trail traffic counters (fig. 5) were used to measure and 

 classify recreational use. Wherever possible, the 

 cameras were focused on the permit-issuing facility to 

 observe compliance/noncompliance directly. Both camera 

 and counters were camouflaged as well as possible. At 

 one location (Spanish Creek), this was impossible because 

 of the exposed location of the information center sign. 

 In this case, the camera was placed farther along the trail 

 to record all visitor use, which was compared to use 

 accounted for by completed permits. 



Figure 4.--Camera used to record trail 

 traffic, mounted in a weatherproof box. 



Figure 5. — Trail traffic counter used to 

 activate ttie camera system. 



The camera-counter systems were fabricated by the 

 Forest Service's Missoula Equipment Development 

 Center.^ A prototype was tested at Spanish Creek in 

 July and August 1977 and performed perfectly. The 

 cameras could be adjusted to run for a variable time per 

 triggering by the traffic counter (up to 252 seconds) and 

 to expose frames at a selected interval (every 2 to 30 

 seconds). The current model also automatically exposed 

 one frame per hour (24 hours per day) while turning on an 

 internal red light to provide an indication of date and 

 passage of time. 



Parties were recorded both entering and leaving; the 

 timing frames helped estimate approximate lengths of stay 

 for day-users. For example, if one red dot separated 

 entrance and exit, the party could only have been up the 

 trail less than 2 hours. It was possible to identify very 

 brief visits and provide additional confirmation of day-use/ 

 camper classifications that were based on the presence/ 

 absence of large packs or packstock. 



Duration and spacing of exposures were set to insure 

 enough information to record the entire party and deter- 

 mine if they obtained a permit (except where the camera 

 was not focused on the information center), while using 

 film at a rate that would not exhaust the film before the 

 next servicing visit. 



'Information on the camera-counter system is available from the Equip- 

 ment Development Center (Gasvoda 1978) 



5 



