feet, but its size is increased enormously after each heavy rain. The 

 water in the upper end of Paper Mill Creek during the six months after 

 planting the fry had an average maximuna temperature of 64, while 

 at the lower end in tide water the average was 71. 



Nicasio Creek rises to the east of Paper Mill Creek, and flows into it 

 about five miles above tide water. Nicasio Creek is very much smaller 

 than the Paper Mill, being only about twenty feet wide, with an average 

 depth of six inches. Throughout its length it flows over flat, gravelly 

 beds, with few trees or bushes to shade the water. The sun has full 

 sweep at it and heats the water each day during the summer to a tem- 

 perature of 75 or 80. 



Olema and Hatchery creeks rise to the west of the main Paper Mill, 

 and flow almost parallel to it, emptying into it near together about one 

 mile below upper tide-water mark. Olema Creek is about the size of 

 Nicasio, but carries more water during the dry season. The water, too, 

 is much cooler, and the upper stream has more of the character of the 

 upper Paper Mill. The banks are thickly grown with brush and trees. 

 The last two miles of the creek runs through low swampy land, with 

 its banks most of the way heavily .lined with willows. The average 

 maximum temperature for lower Olema was 63, and the upper stream 

 averaged but one degree colder. 



Hatchery Creek is very much smaller than Olema Creek, and is not 

 nearly so long. At first fed by springs and running through cool, 

 shady woods, the water is quite cold, but on gaining the open valley and 

 running through two miles of marshy lowlands, with but little shade, 

 it becomes, on reaching Paper Mill Creek, even warmer than the water 

 in Olema Creek. The average maximum temperature of the upper 

 Hatchery Creek was 54, while at the lower end the average was 64. 



The species of fish found in these streams are limited to four. The 

 most important is the steelhead (Salmo gairdneri), which runs in from 

 salt water each winter and spawns in the streams, keeping them well 

 stocked with young trout. About the most abundant fish is the "chub" 

 (Rutilus symmetricus) . The "stickle-back" (Gasterosteus cataphractus) 

 and "blob" (Coitus gulosas) are fairly abundant. Occasionally the dog 

 salmon (Oncorhynchus keta) enters these streams and spawns. 



Tomales Bay, nowhere deep, grows very shallow at its upper end, 

 where it receives Paper Mill Creek. No bar ever forms across the mouth 

 of the creek, as is the case in most of the small coast streams, but is 

 always open for fish to run either in or out. Temperature of Tomales 

 Bay at its upper end averaged 70. 



