INTRODUCTION 



Wilderness management requires reasonably accurate 

 basic data on recreational use. Most wilderness values 

 result from recreation use and so do most threats to the 

 preservation of wilderness values. As a result, most wilder- 

 ness management involves managing visitor use (Hendee 

 and others 1978). This requires reliable data, including 

 information about how much use occurs at different places 

 within a wilderness, what type of use it is (methods of 

 travel, party size, lengths of stay, and perhaps types of 

 activities engaged in), and when it occurs. 



Planning to modify use, to alter trail systems, or to add 

 or close campsites; estimation of ecological impacts; 

 scheduling public contact specialists; and so on, all 

 depend on use data. Evaluating the success of manage- 

 ment efforts in meeting objectives also requires reason- 

 ably accurate use data. 



With some exceptions, wilderness recreational use 

 data are low in accuracy. Methods that yield reasonably 

 accurate data at acceptable cost are needed, both for 

 management and to provide basic data for research on 

 ecological impacts, crowding perceptions, use distribu- 

 tions, and trends over time. Better use measurement was 

 one of the research needs listed most often by respondents 

 in a recent survey of wilderness managers in all agencies 

 (Washburne in press). 



Use Measurement Methods 



Wilderness use is one of the most difficult types of 

 recreational use to measure. The typical wilderness has 

 many access points, usually distant from Ranger Stations 

 and difficult to check. Compared to developed sites, use 

 is light and variable (wilderness recreation is, by definition, 

 low density). This makes it prohibitively expensive to 

 observe all entry points—some would have no use at all on 

 certain days. Use is so widely dispersed that it is nearly 

 impossible to make a direct head count, as could be done 

 in developed auto-access campgrounds. Therefore, a 

 variety of indirect ways of measuring wilderness use have 

 been devised: sample observations, electronic counters, 

 automatic cameras, estimates based on data from trail 

 registers or mandatory permits, or guessing, based on 

 informal, unsystematic observations.' 



A survey of wilderness managers (Washburne in 

 press) shows informal observation is the most common 

 measurement technique (37 percent of all wilderness). 

 Permits are almost as common (36 percent). The remain- 

 der (27 percent) use trail registers, and about half of these 

 do some checking to calibrate or relate register data to 

 actual use. 



Observing a sample of trailheads on sample days 

 produces accurate estimates (Lucas and others 1971; 

 Lucas and Oltman 1971), but the highly variable use makes 

 reliable sampling difficult and costly. Observers must 

 sit near trails in all kinds of weather, often with long periods 

 in which there is no use to observe. 



In addition to entry point sampling, traffic has been 

 sampled at checkpoints on access roads (Lucas 1964). In 

 many areas, one road serves several entry points and 

 results in more use being sampled for the same effort than 

 sampling at trailheads. 



Automatic electronic trail traffic counters have been 

 tried with varying success (Lucas and others 1971; James 

 and Schreuder 1972). An improved model that projects 

 an invisible infrared beam onto a reflector and registers 

 a count when the beam is interrupted has been developed 

 and tested successfully (Tietz 1973). (We used these 

 counters in this study, and they worked well.) At best, 

 however, the counters can indicate the number of large, 

 moving objects passing since the last time the counter 

 was read. The counters cannot indicate whether the ob- 

 jects were hikers, packhorses, elk,- or cows; when they 

 passed; or how they clustered into parties. There are 

 counters that print out counts and times, but they are 

 expensive. Length of stay or information about activities 

 cannot be obtained from the counters. Neither can direc- 

 tion (entry or exit) or route of travel. 



Automatic movie cameras, set to expose one frame 

 at preset intervals, say every 30 seconds, have been used 

 by the National Park Service (Marnell 1977) to estimate 

 use of several wild rivers. Other recording systems employ 

 a movie camera to film a few frames when triggered by a 

 passing object that interrupts an infrared beam. In either 

 case, group size and type of boat usually can be de- 

 termined. To protect privacy, individuals are not identified, 

 and only public areas through which visitors pass are 

 filmed, not campsites or swimming areas. Such systems 

 appear to have the potential for accurate use measurement, 

 but are probably too expensive for routine, annual use at all 

 entry points to typical wilderness areas with many entry 

 points. Cameras avoid problems of discomfort caused by 

 weather and boredom that afflict human observers, and 

 they are much cheaper. 



Many estimates of wilderness use are based on 

 voluntary self-registration at trail registers. Trail registers 

 provide much more complete information than traffic 

 counters. Party size, method of travel, date of entry, 

 length of stay, some data on destination (or itinerary) 

 and activities, and visitor residence are usually obtained. 

 The problem, of course, is that some visitors do not register 

 (Lucas 1975; Lucas and others 1971; Wenger and 

 Gregersen 1964). Some kinds of visitors— especially 

 horsemen, hunters, people making very short visits, and 

 lone individuals— are less likely to register than others. 

 Thus, the resulting registration data not only under- 

 estimate use, but also provide biased estimates of its 

 composition. 



Efforts have been made to develop systems for basing 

 estimates on voluntary trail register data (James and 

 Schreuder 1971; Lucas and others 1971). In effect, adjust- 

 ment factors are applied to raw data from the trail register 

 cards to compensate for nonregistration. A sample of 

 registration behavior is observed to develop the adjustment 

 factors. 



'More than a dozen studies of use estimation for wilderness and dispersed 

 recreation are reviewed by George A. James (1971). 



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