OPINION
COATS, Judge.Alephe Morris and Sudie Burnham were arrested and charged with possession of cocaine. They moved to suppress the cocaine seized at the time of their arrest on three independent grounds. An evidentiary hearing was held on June 28,1982, before Superior Court Judge Thomas E. Schulz. Judge Schulz granted the motion by written memorandum of decision and order, dated October 22, 1982. The state petitioned for review, which this court granted on January 12, 1983.
For purposes of the petition for review the state has adopted the detailed outline of facts contained in the trial court’s order, which in turn was derived from a stipulation between the parties and the testimony at the suppression hearing. Morris and Burnham accept the statement of facts, but cite in addition testimony given at the evi-dentiary hearing. We have accepted the *859additional facts which have been referred to by Morris and Burnham as true for purposes of reviewing this petition.
FACTS
We have set out Judge Schulz’ decision, including footnotes, hereafter:
Early in the day of April 8, 1982, an Alaska Airlines employee named De Alesan-dro received a “goldstreak” package addressed to Alephe Morris, the Alaska State Legislature, Pouch 5, Juneau, Alaska 99811. The goldstreak label also had a phone number for Alaska Airlines to call upon arrival of the package in Juneau. That number was 465-5766, the telephone number for an office of the State Legislature by whom Alephe Morris was employed.
De Alesandro, on his own and for purely airline reasons, x-rayed the package to determine that it contained “only papers” as was represented. The x-ray machine disclosed that the package contained something other than papers, something that De Alesandro thought could possibly be drugs, and he notified Agent Paul Wallace of the Drug Enforcement Administration. Agent Wallace came to the Alaska Airline counter and took the package to a D.E.A. office. He did not open it arid he did not x-ray it but he did arrange ... [for] a “sniff” by a dog trained to “alert” on certain drugs or narcotics. The dog “Ryker” had a history of successful alerts on packages containing drugs1 and he alerted on the package addressed to Ms. Morris. Wallace returned the package to Alaska Airlines, unopened and otherwise uninspected and it was thereafter shipped to Ms. Morris on Flight 62 from San Francisco to Seattle and on Flight 69 from Seattle to Juneau, arriving in [the] evening hours of April 8, 1982.
In the meantime, Agent Wallace contacted the Alaska State Troopers and after he verified that Wallace was who he said he was, Sgt. Glass of the troopers called Wallace back and obtained information which formed the basis for a search warrant2 issued by District Court Judge Gerald Williams.
After obtaining the warrant, Sgt. Glass, Lt. Roger McCoy, Alaska State Troopers, and Officer Nancy Peterson of the Division of Fish and Wildlife Protection went to the terminal building at the Juneau Airport to observe who picked up the goldstreak package and to establish surveillance so that the package and whoever picked it up could be followed to wherever the package was taken.3 There were other law enforcement personnel located in vehicles at strategic points along exit routes from the airport complex and there was radio communication between all officers involved.
About 11:00 p.m. defendants approached the Alaska Airline goldstreak counter and Ms. Morris inquired about the package.4 It was some twenty minutes to one-half hour before airlines personnel were able to deliver the package to Ms. Morris, and during this period of time, Officer Peterson moved toward a public telephone in order to observe the two women from a better angle. At the time she picked up the telephone, Officer Peterson recognized Mrs. Burnham, a friend of hers and the two women greeted one another with a hug. Officer Peterson was introduced to Alephe Morris. During a brief conversation, Officer Peterson invited *860Mrs. Burnham to meet her later at a downtown Juneau hotel. Mrs. Burnham declined, saying she was tired and was going to go home.
Shortly after Officer Peterson left the counter area, the package was delivered to Alephe Morris, who signed for it and the two women left the airport in an automobile registered to Richard and Sudie Burn-ham and operated by Sudie Burnham.
As the Burnham vehicle left the airport it was followed by Peterson, Glass and McCoy, each in separate vehicles. In the vicinity of the Black Angus Restaurant, Burnham, with Morris still in the car, crossed over the Egan Expressway onto Old Glacier Highway. Lt. McCoy followed while Peterson and Glass turned toward Juneau on Egan Expressway.
McCoy was ultimately forced to pass Burnham when she slowed down but Officer McCracken, of the Juneau Police Department, took McCoy’s place and followed Burnham to 4½ Mile Old Glacier Highway where she turned in and stopped at the Burnham residence, where both women exited the car and entered the residence.
While no one involved in the surveillance was able to see whether the package was taken into the residence by either of the women, Sgt. Glass was able to look inside the Burnham vehicle while it was parked in the driveway and observe wrapping paper, apparently from the package, but no package itself. Glass returned to the other officers and told them to prepare to enter the Burnham residence.
It is now some 15 to 20 minutes since the two women entered the Burnham residence and just as the officers began their approach from a point down the road, the Burnham automobile was observed to be leaving the driveway. No one had seen either woman leave the residence and enter the vehicle. Sgt. Glass followed the vehicle 400 or 500 yards down the road and stopped it, after which he and Trooper McCoy approached the vehicle and asked the occupants to get out, which they did. Mrs. Burnham asked why she was being stopped and was told by Sgt. Glass that the police believed that a package picked up at the Juneau airport contained narcotic drugs and they were conducting an investigation. At about this time Officers McCracken, Peterson, Bowman, Glass, McCoy and the district attorney were all visible to Mrs. Burn-ham.
The two women were advised of their Miranda rights and each indicated a desire to have an attorney present. Sgt. Glass interpreted this as a desire on the part of each to remain silent.
Glass took Mrs. Burnham to his vehicle where he advised her that he had a search warrant for her residence, that he knew what was in the package and asked if she would consent to a search of her car. Burn-ham wanted to know if a search of her residence would be necessary if she consented to a search of her car. Glass conferred with the district attorney and advised Burn-ham that if what they were looking for was found in the car, the residence would not be searched. Burnham signed a waiver for a search of the automobile.
During the time of Glass’ original request of Mrs. Burnham for consent to search the vehicle, McCoy observed the package inside the vehicle while he was standing on the passenger side looking through the windshield. McCoy informed Glass of this fact when Glass went to talk to the district attorney, but Glass never told Burnham that McCoy had seen the package.5
Once Burnham consented to a search of the vehicle, the officers entered the car and removed the package, which had been opened, but then reclosed so that the contents were not visible. The brown paper wrapping was lying where Glass had earlier observed it, and he would have seen the package at the same time had it been on the floor in front of the passenger seat when he looked into the vehicle as it was parked in the Burnham driveway. In any event, the package was opened, the con*861tents seized and the two women taken to Johnson Human Resource Center. [Our quotation from Judge Schulz’ decision ends here.]
DISCUSSION
Morris and Burnham apparently argued that the “search” by De Alesandro was not for a legitimate airline purpose; that the activities of the D.E.A. agent (Wallace) were improper; and that the Alaska search warrant should not have been issued nor the package seized from Burnham’s vehicle.
Judge Schulz ruled that the inspection by De Alesandro was not prohibited. With regard to the activities of Wallace, Judge Schulz explicitly found that, contrary to the assertion of Morris and Burnham, Wallace did not x-ray the package, and that the information received by Wallace from De Alesandro was sufficient to justify detention of the package and the sniff-search by the canine agent, Ryker. As to the warrant, Judge Schulz held that while there was a sufficient showing of probable cause for the issuance of a warrant, the one issued here did not comport with the basic requirements for anticipatory warrants under Johnson v. State, 617 P.2d 1117 (Alaska 1980), and thus could not support the search of the package. He also rejected the state’s argument that Burnham had consented to the search of her vehicle, citing Bumper v. North Carolina, 391 U.S. 543, 88 S.Ct. 1788, 20 L.Ed.2d 797 (1968). Finally, Judge Schulz concluded that while seizure of the package could be upheld either on the basis of the “plain view” doctrine or as the result of a legitimate search incident to arrest, neither theory would support the immediate opening of the package. Therefore, Judge Schulz ruled that the contents of the package would not be admissible at trial.
The state petitioned for review, characterizing Judge Schulz’ ruling regarding the warrant as based upon “the failure to particularly specify the place to be searched for the package,” and arguing (1) that the warrant had no such defect and (2) that the portion of the warrant that allowed opening of the package could be severed from any defective portion and applied to the ultimate seizure under the plain view or incident to arrest theories. We conclude that Judge Schulz erred in suppressing the contents of the package which the police seized and find that the package was properly opened pursuant to the warrant.
The warrant provided, after finding probable cause:
“You are therefore commanded in the evening, after the arrival of FI. 69 on 4/8/82 to make search on the person of: (4) Alephe Morris or whoever picks up said package or the premises situated at: (5) wherever the described package is taken to (and you may enter and search for said package upon having followed it to the place into which it is taken and you may open said package and identify and seize its contents for the following property: The above described package ...”
The warrant is obviously an anticipatory warrant — a warrant which is based upon an affidavit which shows probable cause at some future time for a search. The general concept of an anticipatory search was approved in Johnson v. State, 617 P.2d 1117 (Alaska 1980).
Anticipatory warrants present difficult drafting problems because the magistrate does not decide that probable cause exists at the time the police obtain the warrant; rather, he decides that probable cause to search exists if particular anticipated events occur in the future. Thus, generally an anticipatory warrant will require the police to decide that the anticipated events, or conditions precedent, have occurred before they can search. This state of events creates a tension between two interests. The fourth amendment requires the decision to authorize a search to be made by a magistrate, not the police.6 On *862the other hand, courts need to encourage the use of warrants by the police and need to recognize that anticipatory warrants meet certain police exigencies.7 The solution to this tension is, of course, to draft the anticipatory warrant narrowly so that the police have as little discretion as possible in determining whether there is probable cause to search. This appears to be more easily said than done.
Judge Schulz ruled that the warrant was invalid and therefore could not be used to justify the search because it was a general warrant in that it did not designate a particular place to be searched. In light of the record before us we believe it is unnecessary for us to decide whether the warrant in question would have been sufficient to permit the search of any residence or automobile to find the package in question. It is only necessary for us to determine that the warrant is not drafted so broadly that it is necessary for us to invalidate the warrant as a general warrant since the package came into the hands of the police in a constitutionally authorized manner so that it was lawfully seized. Although the warrant did not designate a particular place which the police were to search, the warrant does not allow the police authority to search any number of places. Rather the warrant anticipates that a person will pick up the package and take it to a place. Assuming the police are able to follow the package to that place, they are then authorized to enter that place and seize the package. The warrant anticipates a search of that particular place and limits the search to a search for that package. We simply do not see this warrant as being so general in nature that the constitution requires us to condemn it as a general warrant and to rule that the warrant was invalid for any purpose.
As it turns out, the police followed the package to a residence. However, they apparently could not tell whether the package entered the residence or remained in the car. After a 15 to 20 minute period, the police legitimately stopped the car and the package legitimately came into police hands because it was in plain view and also because the police could seize it incident to the arrest of the occupants of the vehicle. We conclude that under these circumstances the police could open the package. They had followed the package as the warrant directed and the package came into their hands legitimately. The fact that they did not have to enter a house to seize the package and that instead the place where the package wound up turned out to be a car rather than a residence should not invalidate the warrant as far as allowing the police to open the package. No one disputes the fact *863that there was probable cause to believe that the package contained contraband at the airport and that the package was adequately described. It is also undisputed that the police knew that the package which they opened was the one described in the warrant. The only question which remains is whether the fact that the police lost sight of the package for 15 to 20 minutes would mean that they had not followed the conditions of the warrant and/or their probable cause no longer existed because they did not observe the package during that short period of time. We do not believe that the fact that the police officers could not see the package during the 15 to 20 minute period is of such significance that we must invalidate the search of the package. When a magistrate issues a warrant which authorizes the police to follow a package of contraband he certainly anticipates that the police will not be able to observe the package at all times and may even temporarily lose sight of the people who have the package. Here the police followed Morris and Burnham directly to a residence. Although the police temporarily did not know where the package was, this fact should not prevent the police from opening the package under the warrant. There will be few times when the police follow such a package when they will not temporarily lose sight of the people being followed or where they can state with certainty that the contraband was not discarded or hidden along the way. Contraband can always be taken out of a package which the police are following and concealed in some way, leaving the police following an empty package. We simply do not see the possibility that something along those lines happened in this case to be any greater than in any other ordinary case. We therefore conclude that after the police properly seized the package of cocaine, the search warrant which they had, which authorized them to search that package, was valid. We accordingly reverse the judgment of the superior court which suppressed the evidence in question.
REVERSED.
. The testimony indicates that “Ryker” had located drugs in various packages or containers over 400 times.
. I do not believe it is necessary, for a disposition of the pending motions, to set out the testimony taken by Judge Williams. It suffices to say that the testimony established probable cause for issuance of the search warrant.
. After a recitation of the probable cause finding, the warrant provided:
You are therefore commanded in the evening, after the arrival of FI. 69 on 4/8/82 to make search on the person of: (4) Alephe Morris or whoever picks up said package or the premises situated at: (5) wherever the described package is taken to (and you may enter and search for said package upon having followed it to the place into which it is taken and you may open said package and identify and seize its contents for the following property: The above described package ...
.Prior to this, the record is devoid of any indication that Mrs. Burnham was involved in any way.
. McCoy observed the package resting on the floor of the vehicle immediately in front of the passenger seat, and he informed Glass of that fact.
. The following language is from Keller v. State, 543 P.2d 1211, 1219 (Alaska 1975):
The purpose of the warrant requirement is to prevent the police from hasty, ill-advised, or unreasonable actions in “the often competitive enterprise of ferreting out crime.” The law allows the police to infringe upon a person’s fundamental right to be free from *862search and seizure only when such infringement is reasonable. The conclusion that the imposition is reasonable should not be drawn by the very persons who are the agency for the deprivation of right, (citation and footnote omitted)
. The policies supporting anticipatory warrants are strong, as explained in Alvidres v. Superior Court, 12 Cal.App.3d 575, 90 Cal.Rptr. 682, 685-86 (Cal.App.1970):
The entire thrust of the exclusionary rule and the cases which have applied it is to encourage the use of search warrants by law enforcement officials.
One of the major difficulties which confronts law enforcement in the attempt to comply with court enunciated requirements for a “reasonable” search and seizure is the time that is consumed in obtaining search warrants.
The speed with which law enforcement is often required to act, especially when dealing with the furtive and transitory activities of persons who traffic in narcotics, demands that the courts make every effort to assist law enforcement in complying with the edicts that the courts themselves have issued.
We must ask ourselves whether the objective of the rule is better served by permitting officers under circumstances similar to the case at bar to obtain a warrant in advance of the delivery of the narcotic or by forcing them to go to the scene without a warrant and there make a decision at the risk of being second-guessed by the judiciary if they are successful in recovering evidence or contraband. We believe that achievement of the goals which our high court had in mind in adopting the exclusionary evidence rule is best attained by permitting officers to seek warrants in advance when they can clearly demonstrate that their right to search will exist within a reasonable time in the future.