Let us throw some high tech to the field and see if the big people can avoid them. Thanks to eBay I acquired 20 spread spectrum radios used for data acquisition. Yes I have been using them for my job for some time now and know what they offer. How does it work you ask? Well one radio is the master and polls the others up to 20 miles LOS (line of sight). The radios return data from the serial port (RS232). the data contains heats sensors(PIR) and seismic (ground vibration) data. The main thing here is passive not active sensors. If the big people can sense passive sensors then they will have to be sharp.
Data is displayed on a computer display and can be real time to the WEB. Polling 18 radios take about 1 minute depending on the amount of data returned and will be displayed on a screen in a chart format with alarm setting by the operator. Real time cameras with IR are possible but not my priority at this time. The ability to see the heat sensors in an area can be used to direct a response team to intercept a target.
From my experience in the past with PIR (passive infrared) data you can detect the size of an animal very easily so an alarm can be introduced for a large signal.
My first test shows the master radio with a 13dbi Yagi can poll a (1) radio 20 miles away line of sight. The remote radio returns data from 4 PIR motion sensors and 1 seismic sensors, the radio is attached near the top of a tree with a solar panel and sensors are above the reach of any (big) primate. Thus the remotes can operate for months at a time if only sunlight can get to them. Good for the south west but not so goos for the Northwest. Currently I have enough hardware to build 4 remote stations with sensors and supporting equipment. The base or master station can be located within 20 miles LOS or closer if location is in high density forest like in the North West The seismic sensors are from the Vietnam era and were used on the ho chi minh trail for detection of troop or solo personal detection. I have only four seismic detectors and looking for more at this time. All this runs on batteries and charged buy a solar panel to give a long life of service. I'm an engineering tech, so excuse my use of english, I'm not stupid just a logical human.

I Need a hot spot and some serious technical people to help in this endeavor. I have lived in the NW and can relocate. I want to find this creature. Anyone interested?